Security: WS-Rollenprüfung, JWT-Cookie statt localStorage, XSS/SSRF-Fixes, RDP-Consent-Secret

- WebSocket Shell/RDP: Rollenprüfung statt nur JWT-Gültigkeit (war: jeder eingeloggte User konnte fremde Agents per Shell/RDP übernehmen) - JWT_SECRET: Server bricht ab statt mit unsicherem Default weiterzulaufen - Auth: Token läuft jetzt über httpOnly-Cookie statt localStorage (XSS-Schutz gegen Session-Diebstahl) - WS-Auth: Token nicht mehr als URL-Query-Param (landete in nginx-Logs), sondern als erste Message bzw. automatisch via Cookie - Frontend: toter Rollen-Check (isSuperAdmin/isAdmin ohne Funktionsaufruf) in AgentDetailPage gefixt - XSS: DOMPurify-Sanitizing für alle marked.parse()-Renderstellen (KI-Antworten, Kommentare, Knowledge Base) - E-Mail: HTML-Escaping für alle ticket-gesteuerten Felder (auch über öffentliche Ticket-Route erreichbar) - SSRF-Schutz beim Knowledge-Base-URL-Import (blockt private/Loopback-Adressen) - TV-Dashboard: Shared-Key statt komplett offenem Endpoint - Striktes Rate-Limit auf /login, must_change_password serverseitig erzwungen - Agent (C#) v2.7.0: RDP-Consent/Disconnect/Capture verlangen jetzt ein Pro-Session-Secret (war: jeder lokale Prozess konnte Consent vortäuschen), DataDir-ACL für agent.log/status.json - FIDO-PINs AES-256-GCM-verschlüsselt statt Klartext, Retention-Job für alte patch_commands/audit_log Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-06-26 13:27:17 +02:00
parent 3ea28def4c
commit 81b1c326fc
47 changed files with 706 additions and 235 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -35,6 +35,7 @@ agent/*.exe
 agent/*.msi
 agent-cs/bin/
 agent-cs/obj/
+agent-cs/publish/

 # Uploads
 backend/uploads/
--- a/agent-cs/AgentWorker.cs
+++ b/agent-cs/AgentWorker.cs
@@ -6,7 +6,7 @@ namespace ITNexusAgent;

 public class AgentWorker
 {
-    private const string Version = "2.6.0";
+    private const string Version = "2.7.0";
    private const string DataDir = @"C:\ProgramData\IT Nexus Agent";
    private const string ConfigPath = @"C:\ProgramData\IT Nexus Agent\config.json";
    private const string StatusPath = @"C:\ProgramData\IT Nexus Agent\status.json";
@@ -24,6 +24,7 @@ public class AgentWorker
    {
        _exePath = System.Diagnostics.Process.GetCurrentProcess().MainModule!.FileName;
        Directory.CreateDirectory(DataDir);
+        SecureDataDir(DataDir);

        if (!File.Exists(ConfigPath))
        {
@@ -176,6 +177,30 @@ public class AgentWorker
        catch { }
    }

+    // Verzeichnis-ACL: nur SYSTEM/Administratoren — verhindert dass normale lokale User
+    // agent.log/status.json lesen (Hostname, letzter User, RDP-/Patch-Aktivität) oder manipulieren.
+    private static void SecureDataDir(string dir)
+    {
+        try
+        {
+            var di = new System.IO.DirectoryInfo(dir);
+            var acl = di.GetAccessControl();
+            acl.SetAccessRuleProtection(true, false);
+            acl.AddAccessRule(new System.Security.AccessControl.FileSystemAccessRule(
+                "SYSTEM", System.Security.AccessControl.FileSystemRights.FullControl,
+                System.Security.AccessControl.InheritanceFlags.ContainerInherit | System.Security.AccessControl.InheritanceFlags.ObjectInherit,
+                System.Security.AccessControl.PropagationFlags.None,
+                System.Security.AccessControl.AccessControlType.Allow));
+            acl.AddAccessRule(new System.Security.AccessControl.FileSystemAccessRule(
+                "Administrators", System.Security.AccessControl.FileSystemRights.FullControl,
+                System.Security.AccessControl.InheritanceFlags.ContainerInherit | System.Security.AccessControl.InheritanceFlags.ObjectInherit,
+                System.Security.AccessControl.PropagationFlags.None,
+                System.Security.AccessControl.AccessControlType.Allow));
+            di.SetAccessControl(acl);
+        }
+        catch { }
+    }
+
    private static void SecureConfigFile(string path)
    {
        try
--- a/agent-cs/CaptureModeRunner.cs
+++ b/agent-cs/CaptureModeRunner.cs
@@ -11,7 +11,7 @@ public static class CaptureModeRunner
    private static readonly ImageCodecInfo JpegCodec =
        ImageCodecInfo.GetImageEncoders().First(c => c.FormatID == ImageFormat.Jpeg.Guid);

-    public static void Run(string portStr, int screenIdx = 0)
+    public static void Run(string portStr, int screenIdx, string secret)
    {
        if (!int.TryParse(portStr, out var port) || port <= 0) return;

@@ -20,6 +20,7 @@ public static class CaptureModeRunner
            using var tcp = new TcpClient();
            tcp.Connect("127.0.0.1", port);
            var stream = tcp.GetStream();
+            stream.Write(System.Text.Encoding.ASCII.GetBytes(secret));

            var encParams = new EncoderParameters(1);
            encParams.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 60L);
--- a/agent-cs/ConsentModeRunner.cs
+++ b/agent-cs/ConsentModeRunner.cs
@@ -5,14 +5,14 @@ namespace ITNexusAgent;
 // Läuft als User-Prozess (via schtasks), zeigt Consent-Dialog und sendet Antwort via TCP
 public static class ConsentModeRunner
 {
-    public static void Run(string portStr)
+    public static void Run(string portStr, string secret)
    {
        if (!int.TryParse(portStr, out var port) || port <= 0) return;

        var app = new System.Windows.Application();
        app.ShutdownMode = System.Windows.ShutdownMode.OnMainWindowClose;

-        var win = new RdpConsentWindow(port);
+        var win = new RdpConsentWindow(port, secret);
        win.Topmost = true;
        win.Show();
        win.Activate();
--- a/agent-cs/IT-Nexus-Agent.csproj
+++ b/agent-cs/IT-Nexus-Agent.csproj
@@ -7,8 +7,8 @@
    <UseWindowsForms>true</UseWindowsForms>
    <AssemblyName>IT-Nexus-Agent</AssemblyName>
    <RootNamespace>ITNexusAgent</RootNamespace>
-    <Version>2.6.0</Version>
-    <AssemblyVersion>2.6.0.0</AssemblyVersion>
+    <Version>2.7.0</Version>
+    <AssemblyVersion>2.7.0.0</AssemblyVersion>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <AllowUnsafeBlocks>false</AllowUnsafeBlocks>
--- a/agent-cs/IndicatorModeRunner.cs
+++ b/agent-cs/IndicatorModeRunner.cs
@@ -6,14 +6,14 @@ namespace ITNexusAgent;
 // solange RDP-Session aktiv ist. User kann selbst trennen (TCP-Signal an Service).
 public static class IndicatorModeRunner
 {
-    public static void Run(string portStr)
+    public static void Run(string portStr, string secret)
    {
        if (!int.TryParse(portStr, out var port) || port <= 0) return;

        var app = new System.Windows.Application();
        app.ShutdownMode = System.Windows.ShutdownMode.OnMainWindowClose;

-        var win = new RdpActiveIndicatorWindow(port);
+        var win = new RdpActiveIndicatorWindow(port, secret);
        win.Show();
        app.Run();
    }
--- a/agent-cs/Program.cs
+++ b/agent-cs/Program.cs
@@ -20,17 +20,22 @@ internal class Program
                    return;

                case "--rdp-consent":
-                    ConsentModeRunner.Run(args.Length > 1 ? args[1] : "");
+                    ConsentModeRunner.Run(
+                        args.Length > 1 ? args[1] : "",
+                        args.Length > 2 ? args[2] : "");
                    return;

                case "--rdp-capture":
                    CaptureModeRunner.Run(
                        args.Length > 1 ? args[1] : "",
-                        args.Length > 2 && int.TryParse(args[2], out var si) ? si : 0);
+                        args.Length > 2 && int.TryParse(args[2], out var si) ? si : 0,
+                        args.Length > 3 ? args[3] : "");
                    return;

                case "--rdp-indicator":
-                    IndicatorModeRunner.Run(args.Length > 1 ? args[1] : "");
+                    IndicatorModeRunner.Run(
+                        args.Length > 1 ? args[1] : "",
+                        args.Length > 2 ? args[2] : "");
                    return;

                case "--dashboard":
--- a/agent-cs/Services/RtcService.cs
+++ b/agent-cs/Services/RtcService.cs
@@ -2,6 +2,7 @@ using System.Diagnostics;
 using System.Net;
 using System.Net.Sockets;
 using System.Net.WebSockets;
+using System.Security.Cryptography;
 using System.Text;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
@@ -112,15 +113,36 @@ public class RtcService
        }
    }

+    private static string GenerateSecret() => Convert.ToHexString(RandomNumberGenerator.GetBytes(16));
+
+    // Liest exakt secret.Length Bytes und vergleicht zeitkonstant — verhindert, dass ein beliebiger
+    // lokaler Prozess sich als der gespawnte Helper ausgibt und Consent/Disconnect/Frames vortäuscht.
+    private static async Task<bool> ValidateSecretAsync(NetworkStream stream, string secret, CancellationToken ct)
+    {
+        var expected = Encoding.ASCII.GetBytes(secret);
+        var buf = new byte[expected.Length];
+        var read = 0;
+        while (read < buf.Length)
+        {
+            int n;
+            try { n = await stream.ReadAsync(buf.AsMemory(read, buf.Length - read), ct); }
+            catch { return false; }
+            if (n == 0) return false;
+            read += n;
+        }
+        return CryptographicOperations.FixedTimeEquals(buf, expected);
+    }
+
    private async Task ConsentAndCaptureAsync(ClientWebSocket ws, int screenIdx, CancellationToken ct)
    {
        var exePath = System.Diagnostics.Process.GetCurrentProcess().MainModule!.FileName;
+        var secret = GenerateSecret();

        var consentListener = new TcpListener(IPAddress.Loopback, 0);
        consentListener.Start();
        var consentPort = ((IPEndPoint)consentListener.LocalEndpoint).Port;

-        if (!SpawnConsentHelper(exePath, consentPort.ToString()))
+        if (!SpawnConsentHelper(exePath, consentPort.ToString(), secret))
        {
            consentListener.Stop();
            AgentWorker.Log("RDP: Consent-Helper fehlgeschlagen, verweigere Zugriff");
@@ -140,9 +162,15 @@ public class RtcService
        {
            using var timeoutCts = new CancellationTokenSource(TimeSpan.FromSeconds(35));
            using var linked = CancellationTokenSource.CreateLinkedTokenSource(ct, timeoutCts.Token);
+            while (!linked.IsCancellationRequested)
+            {
                using var tcp = await consentListener.AcceptTcpClientAsync(linked.Token);
-            var b = tcp.GetStream().ReadByte();
+                var stream = tcp.GetStream();
+                if (!await ValidateSecretAsync(stream, secret, linked.Token)) continue; // fremder Connect-Versuch ohne gültiges Secret — ignorieren, weiter warten
+                var b = stream.ReadByte();
                accepted = b == 1;
+                break;
+            }
        }
        catch { accepted = false; }
        finally { consentListener.Stop(); }
@@ -174,6 +202,7 @@ public class RtcService
            _indicatorListener = new TcpListener(IPAddress.Loopback, 0);
            _indicatorListener.Start();
            var port = ((IPEndPoint)_indicatorListener.LocalEndpoint).Port;
+            var secret = GenerateSecret();

            _userDisconnectCts = new CancellationTokenSource();
            var listener = _indicatorListener;
@@ -181,16 +210,22 @@ public class RtcService
            _ = Task.Run(async () =>
            {
                try
+                {
+                    while (true)
                    {
                        using var tcp = await listener.AcceptTcpClientAsync();
-                    tcp.GetStream().ReadByte();
+                        var stream = tcp.GetStream();
+                        if (!await ValidateSecretAsync(stream, secret, CancellationToken.None)) continue; // fremder Connect-Versuch ohne gültiges Secret
+                        stream.ReadByte();
                        disconnectCts.Cancel();
                        AgentWorker.Log("RDP: User hat über Overlay getrennt");
+                        break;
+                    }
                }
                catch { }
            });

-            _indicatorPid = SessionSpawner.SpawnInUserSession(exePath, $"--rdp-indicator {port}");
+            _indicatorPid = SessionSpawner.SpawnInUserSession(exePath, $"--rdp-indicator {port} {secret}");
        }
        catch (Exception ex)
        {
@@ -198,22 +233,23 @@ public class RtcService
        }
    }

-    private static bool SpawnConsentHelper(string exePath, string portStr)
+    private static bool SpawnConsentHelper(string exePath, string portStr, string secret)
    {
-        var pid = SessionSpawner.SpawnInUserSession(exePath, $"--rdp-consent {portStr}");
+        var pid = SessionSpawner.SpawnInUserSession(exePath, $"--rdp-consent {portStr} {secret}");
        return pid > 0;
    }

    private async Task CapturePipeLoopAsync(ClientWebSocket ws, int screenIdx, CancellationToken ct)
    {
        var exePath = System.Diagnostics.Process.GetCurrentProcess().MainModule!.FileName;
+        var secret = GenerateSecret();

        // TCP Loopback: kein ACL-Problem zwischen SYSTEM-Service und User-Prozess
        var listener = new TcpListener(IPAddress.Loopback, 0);
        listener.Start();
        var port = ((IPEndPoint)listener.LocalEndpoint).Port;

-        if (!SpawnCaptureHelper(exePath, port.ToString(), screenIdx))
+        if (!SpawnCaptureHelper(exePath, port.ToString(), screenIdx, secret))
        {
            listener.Stop();
            AgentWorker.Log("RDP: Helper-Start fehlgeschlagen");
@@ -225,7 +261,16 @@ public class RtcService
        {
            using var connectCts = new CancellationTokenSource(TimeSpan.FromSeconds(15));
            using var linked = CancellationTokenSource.CreateLinkedTokenSource(ct, connectCts.Token);
-            tcp = await listener.AcceptTcpClientAsync(linked.Token);
+            while (true)
+            {
+                var candidate = await listener.AcceptTcpClientAsync(linked.Token);
+                if (await ValidateSecretAsync(candidate.GetStream(), secret, linked.Token))
+                {
+                    tcp = candidate;
+                    break;
+                }
+                candidate.Dispose(); // fremder Connect-Versuch ohne gültiges Secret — verwerfen, weiter warten
+            }
        }
        catch
        {
@@ -283,9 +328,9 @@ public class RtcService
        AgentWorker.Log("RDP: Frame-Loop beendet");
    }

-    private static bool SpawnCaptureHelper(string exePath, string portStr, int screenIdx = 0)
+    private static bool SpawnCaptureHelper(string exePath, string portStr, int screenIdx, string secret)
    {
-        var pid = SessionSpawner.SpawnInUserSession(exePath, $"--rdp-capture {portStr} {screenIdx}");
+        var pid = SessionSpawner.SpawnInUserSession(exePath, $"--rdp-capture {portStr} {screenIdx} {secret}");
        return pid > 0;
    }
 }
--- a/agent-cs/UI/RdpActiveIndicatorWindow.xaml.cs
+++ b/agent-cs/UI/RdpActiveIndicatorWindow.xaml.cs
@@ -1,4 +1,5 @@
 using System.Net.Sockets;
+using System.Text;
 using System.Windows;
 using System.Windows.Media.Animation;

@@ -7,14 +8,16 @@ namespace ITNexusAgent.UI;
 public partial class RdpActiveIndicatorWindow : Window
 {
    private readonly int _port;
+    private readonly string _secret;
    private readonly DateTime _startedAt = DateTime.Now;
    private readonly System.Windows.Threading.DispatcherTimer _timer = new();
    private bool _signaled = false;

-    public RdpActiveIndicatorWindow(int port)
+    public RdpActiveIndicatorWindow(int port, string secret)
    {
        InitializeComponent();
        _port = port;
+        _secret = secret;

        Loaded += (s, e) =>
        {
@@ -47,8 +50,10 @@ public partial class RdpActiveIndicatorWindow : Window
        {
            using var tcp = new TcpClient();
            tcp.Connect("127.0.0.1", _port);
-            tcp.GetStream().WriteByte(1);
-            tcp.GetStream().Flush();
+            var stream = tcp.GetStream();
+            stream.Write(Encoding.ASCII.GetBytes(_secret));
+            stream.WriteByte(1);
+            stream.Flush();
        }
        catch { }
    }
--- a/agent-cs/UI/RdpConsentWindow.xaml.cs
+++ b/agent-cs/UI/RdpConsentWindow.xaml.cs
@@ -1,4 +1,5 @@
 using System.Net.Sockets;
+using System.Text;
 using System.Windows;

 namespace ITNexusAgent.UI;
@@ -6,13 +7,15 @@ namespace ITNexusAgent.UI;
 public partial class RdpConsentWindow : Window
 {
    private readonly int _port;
+    private readonly string _secret;
    private bool _answered = false;
    private System.Threading.CancellationTokenSource _countdownCts = new();

-    public RdpConsentWindow(int port)
+    public RdpConsentWindow(int port, string secret)
    {
        InitializeComponent();
        _port = port;
+        _secret = secret;
        _ = RunCountdownAsync(_countdownCts.Token);
    }

@@ -53,8 +56,10 @@ public partial class RdpConsentWindow : Window
        {
            using var tcp = new TcpClient();
            tcp.Connect("127.0.0.1", _port);
-            tcp.GetStream().WriteByte((byte)(accepted ? 1 : 0));
-            tcp.GetStream().Flush();
+            var stream = tcp.GetStream();
+            stream.Write(Encoding.ASCII.GetBytes(_secret));
+            stream.WriteByte((byte)(accepted ? 1 : 0));
+            stream.Flush();
        }
        catch { }
    }
--- a/agent-cs/setup.iss
+++ b/agent-cs/setup.iss
@@ -1,5 +1,5 @@
 #define MyAppName "IT Nexus Agent"
-#define MyAppVersion "2.6.0"
+#define MyAppVersion "2.7.0"
 #define MyAppPublisher "Cereda Systems GmbH"
 #define MyAppURL "https://it-nexus.cereda-systems.de"
 #define MyAppExeName "IT-Nexus-Agent.exe"
--- a/backend/package-lock.json
+++ b/backend/package-lock.json
@@ -14,6 +14,7 @@
        "better-sqlite3": "^12.6.2",
        "botbuilder": "^4.23.3",
        "bwip-js": "^4.8.0",
+        "cookie-parser": "^1.4.7",
        "cors": "^2.8.5",
        "dotenv": "^16.3.1",
        "express": "^4.18.2",
@@ -1371,6 +1372,25 @@
        "node": ">= 0.6"
      }
    },
+    "node_modules/cookie-parser": {
+      "version": "1.4.7",
+      "resolved": "https://registry.npmjs.org/cookie-parser/-/cookie-parser-1.4.7.tgz",
+      "integrity": "sha512-nGUvgXnotP3BsjiLX2ypbQnWoGUPIIfHQNZkkC668ntrzGWEZVW70HDEB1qnNGMicPje6EttlIgzo51YSwNQGw==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "0.7.2",
+        "cookie-signature": "1.0.6"
+      },
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
+    "node_modules/cookie-parser/node_modules/cookie-signature": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
+      "integrity": "sha512-QADzlaHc8icV8I7vbaJXJwod9HWYp8uCqf1xa4OfNu1T7JVxQIrUgOWtHdNDtPiywmFbiS12VjotIXLrKM3orQ==",
+      "license": "MIT"
+    },
    "node_modules/cookie-signature": {
      "version": "1.0.7",
      "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.7.tgz",
--- a/backend/package.json
+++ b/backend/package.json
@@ -21,6 +21,7 @@
    "better-sqlite3": "^12.6.2",
    "botbuilder": "^4.23.3",
    "bwip-js": "^4.8.0",
+    "cookie-parser": "^1.4.7",
    "cors": "^2.8.5",
    "dotenv": "^16.3.1",
    "express": "^4.18.2",
--- a/backend/src/config/jwt.js
+++ b/backend/src/config/jwt.js
@@ -1,14 +1,14 @@
 require('dotenv').config();

+if (!process.env.JWT_SECRET) {
+    console.error('❌ FATAL: JWT_SECRET ist nicht gesetzt. Server wird nicht mit einem unsicheren Default-Secret gestartet.');
+    process.exit(1);
+}
+
 const JWT_CONFIG = {
-    secret: process.env.JWT_SECRET || 'default-secret-change-in-production',
+    secret: process.env.JWT_SECRET,
    expiresIn: process.env.JWT_EXPIRATION || '8h',
    algorithm: 'HS256'
 };

-// Validate that JWT_SECRET is set
-if (!process.env.JWT_SECRET) {
-    console.warn('⚠️  WARNING: JWT_SECRET not set in .env file. Using default secret (INSECURE!)');
-}
-
 module.exports = JWT_CONFIG;
--- a/backend/src/controllers/ai.controller.js
+++ b/backend/src/controllers/ai.controller.js
@@ -160,8 +160,12 @@ class AiController {
        const { url } = req.body;
        if (!url?.trim()) throw new AppError('URL ist erforderlich', 400);

-        // Only allow http/https
-        if (!/^https?:\/\//i.test(url)) throw new AppError('Nur HTTP/HTTPS URLs erlaubt', 400);
+        const { assertPublicUrl } = require('../utils/ssrfGuard');
+        try {
+            await assertPublicUrl(url);
+        } catch (e) {
+            throw new AppError(e.message, 400);
+        }

        let html;
        try {
@@ -204,7 +208,12 @@ class AiController {
        const AiService = require('../services/ai.service');
        const { url, maxPages = 20 } = req.body;
        if (!url?.trim()) throw new AppError('URL ist erforderlich', 400);
-        if (!/^https?:\/\//i.test(url)) throw new AppError('Nur HTTP/HTTPS URLs erlaubt', 400);
+        const { assertPublicUrl } = require('../utils/ssrfGuard');
+        try {
+            await assertPublicUrl(url);
+        } catch (e) {
+            throw new AppError(e.message, 400);
+        }

        const limit = Math.min(Math.max(1, parseInt(maxPages) || 20), 100);
        const baseUrl = new URL(url);
@@ -236,6 +245,7 @@ class AiController {
            visited.add(currentUrl);

            try {
+                try { await assertPublicUrl(currentUrl); } catch { continue; } // DNS-Rebinding-Schutz
                const response = await fetch(currentUrl, {
                    headers: { 'User-Agent': 'Mozilla/5.0 IT-Nexus KnowledgeBase Importer' },
                    signal: AbortSignal.timeout(10000),
--- a/backend/src/controllers/auth.controller.js
+++ b/backend/src/controllers/auth.controller.js
@@ -1,6 +1,7 @@
 const AuthService = require('../services/auth.service');
 const User = require('../models/User');
 const { asyncHandler } = require('../middleware/errorHandler');
+const { setAuthCookie, clearAuthCookie } = require('../utils/authCookie');

 class AuthController {
    /**
@@ -18,10 +19,11 @@ class AuthController {
        }

        const result = await AuthService.login(username, password);
+        setAuthCookie(res, result.token);

        res.json({
            status: 'success',
-            data: result
+            data: { user: result.user }
        });
    });

@@ -104,8 +106,7 @@ class AuthController {
     * POST /api/auth/logout
     */
    static logout = asyncHandler(async (req, res) => {
-        // Client-side will handle token removal
-        // This endpoint is just for consistency and potential future server-side session handling
+        clearAuthCookie(res);
        res.json({
            status: 'success',
            message: 'Logged out successfully'
--- a/backend/src/db/seed.js
+++ b/backend/src/db/seed.js
@@ -481,6 +481,7 @@ async function initializeDatabase() {
        `ALTER TABLE fido_keys ADD COLUMN last_used_at DATETIME`,
        `ALTER TABLE fido_keys ADD COLUMN manufacturer TEXT`,
        `ALTER TABLE fido_keys ADD COLUMN connection_type TEXT`,
+        `ALTER TABLE fido_keys ADD COLUMN pin TEXT`,
        // Asset-Agent-Sync
        `ALTER TABLE assets ADD COLUMN os TEXT`,
        `ALTER TABLE assets ADD COLUMN ip_address TEXT`,
@@ -552,6 +553,23 @@ async function initializeDatabase() {
        }
        console.log('✅ Database migrations completed');

+        // Special migration: bestehende Klartext-PINs in fido_keys nachverschlüsseln (DSGVO Art. 32)
+        try {
+            const { encrypt } = require('../utils/crypto');
+            const plainPinRows = db.prepare(
+                `SELECT id, pin FROM fido_keys WHERE pin IS NOT NULL AND pin != '' AND instr(pin, ':') = 0`
+            ).all();
+            if (plainPinRows.length > 0) {
+                const updatePin = db.prepare('UPDATE fido_keys SET pin = ? WHERE id = ?');
+                for (const row of plainPinRows) {
+                    updatePin.run(encrypt(row.pin), row.id);
+                }
+                console.log(`🔐 ${plainPinRows.length} Klartext-PIN(s) in fido_keys nachverschlüsselt`);
+            }
+        } catch (e) {
+            console.error('⚠️  PIN-Verschlüsselungs-Migration fehlgeschlagen:', e.message);
+        }
+
        // Special migration: rebuild network_devices to add SNMP + AP support
        try {
            const ndDef = db.prepare("SELECT sql FROM sqlite_master WHERE type='table' AND name='network_devices'").get();
--- a/backend/src/middleware/auth.js
+++ b/backend/src/middleware/auth.js
@@ -1,6 +1,9 @@
 const jwt = require('jsonwebtoken');
 const JWT_CONFIG = require('../config/jwt');

+// Endpunkte, die trotz erzwungenem Passwortwechsel erreichbar bleiben müssen
+const PASSWORD_CHANGE_EXEMPT_PATHS = ['/api/auth/me', '/api/auth/change-password'];
+
 /**
 * Middleware to verify JWT token and attach user to request
 */
@@ -18,6 +21,19 @@ function authenticateToken(req, res, next) {
    try {
        const decoded = jwt.verify(token, JWT_CONFIG.secret);
        req.user = decoded; // { id, username, email, role, roleId }
+
+        if (!PASSWORD_CHANGE_EXEMPT_PATHS.includes(req.originalUrl.split('?')[0])) {
+            const User = require('../models/User');
+            const dbUser = User.getById(decoded.id);
+            if (dbUser?.must_change_password) {
+                return res.status(403).json({
+                    status: 'error',
+                    code: 'PASSWORD_CHANGE_REQUIRED',
+                    message: 'Passwortänderung erforderlich, bevor weitere Aktionen möglich sind'
+                });
+            }
+        }
+
        next();
    } catch (error) {
        if (error.name === 'TokenExpiredError') {
--- a/backend/src/models/AuditLog.js
+++ b/backend/src/models/AuditLog.js
@@ -105,6 +105,16 @@ class AuditLog {
        return stmt.all(limit);
    }

+    /**
+     * Löscht Audit-Log-Einträge älter als retentionDays (DSGVO Art. 5 Abs. 1 lit. e - Speicherbegrenzung)
+     */
+    static cleanupOld(retentionDays = 180) {
+        const db = getDatabase();
+        const stmt = db.prepare(`DELETE FROM audit_log WHERE created_at < datetime('now', '-' || ? || ' days')`);
+        const result = stmt.run(retentionDays);
+        return result.changes;
+    }
+
    /**
     * Helper method to log user actions
     */
--- a/backend/src/models/FidoKey.js
+++ b/backend/src/models/FidoKey.js
@@ -1,4 +1,10 @@
 const { getDatabase } = require('../config/database');
+const { encrypt, decrypt } = require('../utils/crypto');
+
+function withDecryptedPin(row) {
+    if (!row) return row;
+    return { ...row, pin: decrypt(row.pin) };
+}

 class FidoKey {
    /**
@@ -19,7 +25,7 @@ class FidoKey {
            LEFT JOIN users uu ON fk.updated_by_user_id = uu.id
            ORDER BY fk.created_at DESC
        `);
-        return stmt.all();
+        return stmt.all().map(withDecryptedPin);
    }

    /**
@@ -40,7 +46,7 @@ class FidoKey {
            LEFT JOIN users uu ON fk.updated_by_user_id = uu.id
            WHERE fk.id = ?
        `);
-        return stmt.get(id);
+        return withDecryptedPin(stmt.get(id));
    }

    /**
@@ -58,7 +64,7 @@ class FidoKey {
            LEFT JOIN users cu ON fk.created_by_user_id = cu.id
            WHERE fk.serial_number = ?
        `);
-        return stmt.get(serialNumber);
+        return withDecryptedPin(stmt.get(serialNumber));
    }

    /**
@@ -77,7 +83,7 @@ class FidoKey {
            WHERE fk.status = ?
            ORDER BY fk.created_at DESC
        `);
-        return stmt.all(status);
+        return stmt.all(status).map(withDecryptedPin);
    }

    /**
@@ -94,7 +100,7 @@ class FidoKey {
            WHERE fk.assigned_to_user_id = ?
            ORDER BY fk.created_at DESC
        `);
-        return stmt.all(userId);
+        return stmt.all(userId).map(withDecryptedPin);
    }

    /**
@@ -108,9 +114,10 @@ class FidoKey {
                serial_number,
                status,
                description,
+                pin,
                assigned_to_user_id,
                created_by_user_id
-            ) VALUES (?, ?, ?, ?, ?, ?)
+            ) VALUES (?, ?, ?, ?, ?, ?, ?)
        `);

        const result = stmt.run(
@@ -118,6 +125,7 @@ class FidoKey {
            keyData.serial_number,
            keyData.status,
            keyData.description || null,
+            encrypt(keyData.pin) || null,
            keyData.assigned_to_user_id || null,
            keyData.created_by_user_id
        );
@@ -150,6 +158,10 @@ class FidoKey {
            fields.push('description = ?');
            values.push(keyData.description);
        }
+        if (keyData.pin !== undefined) {
+            fields.push('pin = ?');
+            values.push(encrypt(keyData.pin));
+        }
        if (keyData.assigned_to_user_id !== undefined) {
            fields.push('assigned_to_user_id = ?');
            values.push(keyData.assigned_to_user_id);
--- a/backend/src/routes/microsoft.auth.routes.js
+++ b/backend/src/routes/microsoft.auth.routes.js
@@ -3,6 +3,7 @@ const router = express.Router();
 const crypto = require('crypto');
 const jwt = require('jsonwebtoken');
 const User = require('../models/User');
+const { setAuthCookie } = require('../utils/authCookie');

 const TENANT_ID = () => process.env.AZURE_TENANT_ID;
 const CLIENT_ID = () => process.env.AZURE_CLIENT_ID;
--- a/backend/src/routes/tv.routes.js
+++ b/backend/src/routes/tv.routes.js
@@ -2,7 +2,15 @@ const express = require('express');
 const router = express.Router();
 const { getStats, getCVEs } = require('../controllers/tv.controller');

-router.get('/stats', getStats);
-router.get('/cves', getCVEs);
+// Kein normaler Login (TV-Display im Büro) — aber ein Shared-Key statt komplett offen ins Netz.
+function requireTvKey(req, res, next) {
+    if (!process.env.TV_DASHBOARD_KEY || req.query.key !== process.env.TV_DASHBOARD_KEY) {
+        return res.status(401).json({ status: 'error', message: 'Unauthorized' });
+    }
+    next();
+}
+
+router.get('/stats', requireTvKey, getStats);
+router.get('/cves', requireTvKey, getCVEs);

 module.exports = router;
--- a/backend/src/server.js
+++ b/backend/src/server.js
@@ -75,6 +75,16 @@ const authLimiter = rateLimit({
    legacyHeaders: false
 });

+// Striktes Limit nur für /login — verhindert Brute-Force auf Passwörter
+const loginLimiter = rateLimit({
+    windowMs: 15 * 60 * 1000,
+    max: 8,
+    message: { status: 'error', message: 'Zu viele Login-Versuche, bitte später erneut versuchen' },
+    standardHeaders: true,
+    legacyHeaders: false,
+    skipSuccessfulRequests: true
+});
+
 // ============================================================================
 // ROUTES
 // ============================================================================
@@ -127,6 +137,7 @@ app.get('/api/health/history', (req, res) => {
 });

 // API routes
+app.use('/api/auth/login', loginLimiter);
 app.use('/api/auth', authLimiter, authRoutes);
 app.use('/api/users', userRoutes);
 app.use('/api/fido-keys', fidoKeyRoutes);
@@ -411,6 +422,12 @@ async function startServer() {
            NetworkDevice.cleanupOldChecks();
        });

+        // DSGVO-Speicherbegrenzung: alte patch_commands (inkl. Shell-Output) + audit_log (täglich 03:30)
+        cron.schedule('30 3 * * *', () => {
+            const { runRetentionCleanup } = require('./services/dataRetention.service');
+            runRetentionCleanup();
+        });
+
        // Proxmox Monitoring (alle 5 Minuten)
        if (process.env.PROXMOX_HOST && process.env.PROXMOX_TOKEN) {
            const { pollProxmox } = require('./services/proxmoxService');
--- a/backend/src/services/dataRetention.service.js
+++ b/backend/src/services/dataRetention.service.js
@@ -0,0 +1,26 @@
+const { getDatabase } = require('../config/database');
+const AuditLog = require('../models/AuditLog');
+
+// DSGVO Art. 5 Abs. 1 lit. e (Speicherbegrenzung) — Daten nur so lange aufbewahren wie nötig.
+const PATCH_COMMANDS_RETENTION_DAYS = parseInt(process.env.PATCH_COMMANDS_RETENTION_DAYS || '90', 10);
+const AUDIT_LOG_RETENTION_DAYS = parseInt(process.env.AUDIT_LOG_RETENTION_DAYS || '180', 10);
+
+function cleanupPatchCommands() {
+    const db = getDatabase();
+    const stmt = db.prepare(
+        `DELETE FROM patch_commands WHERE created_at < datetime('now', '-' || ? || ' days') AND status IN ('done', 'failed')`
+    );
+    return stmt.run(PATCH_COMMANDS_RETENTION_DAYS).changes;
+}
+
+function runRetentionCleanup() {
+    try {
+        const patchDeleted = cleanupPatchCommands();
+        const auditDeleted = AuditLog.cleanupOld(AUDIT_LOG_RETENTION_DAYS);
+        console.log(`[DataRetention] Bereinigt: ${patchDeleted} patch_commands (>${PATCH_COMMANDS_RETENTION_DAYS}d), ${auditDeleted} audit_log Einträge (>${AUDIT_LOG_RETENTION_DAYS}d)`);
+    } catch (err) {
+        console.error('[DataRetention] Fehler:', err.message);
+    }
+}
+
+module.exports = { runRetentionCleanup, cleanupPatchCommands };
--- a/backend/src/services/email.service.js
+++ b/backend/src/services/email.service.js
@@ -431,9 +431,9 @@ async function sendTicketCreatedConfirmation(ticket) {
      </p>

      ${infoCard([
-          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${ticket.ticket_number}</strong>`],
-          ['Betreff', `<strong style="color:#111827;">${ticket.title}</strong>`],
-          ['Kategorie', `<span style="color:#374151;">${ticket.category}</span>`],
+          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${escHtml(ticket.ticket_number)}</strong>`],
+          ['Betreff', `<strong style="color:#111827;">${escHtml(ticket.title)}</strong>`],
+          ['Kategorie', `<span style="color:#374151;">${escHtml(ticket.category)}</span>`],
          ['Priorität', priorityBadge(ticket.priority)],
          ['Status', statusBadge(ticket.status)],
      ])}
@@ -494,11 +494,11 @@ async function sendTicketAssignedNotification(ticket, assignedUser) {
      </p>

      ${infoCard([
-          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${ticket.ticket_number}</strong>`],
-          ['Betreff', `<strong style="color:#111827;">${ticket.title}</strong>`],
-          ['Kategorie', `<span style="color:#374151;">${ticket.category}</span>`],
+          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${escHtml(ticket.ticket_number)}</strong>`],
+          ['Betreff', `<strong style="color:#111827;">${escHtml(ticket.title)}</strong>`],
+          ['Kategorie', `<span style="color:#374151;">${escHtml(ticket.category)}</span>`],
          ['Priorität', priorityBadge(ticket.priority)],
-          ['Von', `<span style="color:#374151;">${ticket.requester_name || 'Unbekannt'}${ticket.requester_email ? ` &lt;${ticket.requester_email}&gt;` : ''}</span>`],
+          ['Von', `<span style="color:#374151;">${escHtml(ticket.requester_name || 'Unbekannt')}${ticket.requester_email ? ` &lt;${escHtml(ticket.requester_email)}&gt;` : ''}</span>`],
      ])}`;

    await sendMail(
@@ -554,10 +554,10 @@ async function sendCommentNotification(ticket, comment) {
            <table cellpadding="0" cellspacing="0" border="0">
              <tr>
                <td bgcolor="#0d9488" style="background-color:#0d9488;border-radius:6px;width:28px;height:28px;text-align:center;vertical-align:middle;padding:0 8px;">
-                  <span style="font-size:13px;font-weight:800;color:#ffffff;font-family:Inter,Helvetica,Arial,sans-serif;line-height:28px;">${authorName.charAt(0).toUpperCase()}</span>
+                  <span style="font-size:13px;font-weight:800;color:#ffffff;font-family:Inter,Helvetica,Arial,sans-serif;line-height:28px;">${escHtml(authorName.charAt(0).toUpperCase())}</span>
                </td>
                <td style="padding-left:10px;vertical-align:middle;">
-                  <span style="font-size:13px;font-weight:700;color:#111827;font-family:Inter,Helvetica,Arial,sans-serif;">${authorName}</span>
+                  <span style="font-size:13px;font-weight:700;color:#111827;font-family:Inter,Helvetica,Arial,sans-serif;">${escHtml(authorName)}</span>
                  <span style="font-size:11px;color:#9ca3af;font-family:Inter,Helvetica,Arial,sans-serif;padding-left:6px;">· IT Support</span>
                </td>
              </tr>
@@ -567,14 +567,14 @@ async function sendCommentNotification(ticket, comment) {
        <!-- Message body -->
        <tr>
          <td bgcolor="#ffffff" style="background-color:#ffffff;padding:16px;font-size:14px;color:#1f2937;line-height:1.75;white-space:pre-line;font-family:Inter,Helvetica,Arial,sans-serif;">
-            ${comment.comment.replace(/</g, '&lt;').replace(/>/g, '&gt;')}
+            ${escHtml(comment.comment)}
          </td>
        </tr>
      </table>

      ${infoCard([
-          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${ticket.ticket_number}</strong>`],
-          ['Betreff', `<span style="color:#374151;">${ticket.title}</span>`],
+          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${escHtml(ticket.ticket_number)}</strong>`],
+          ['Betreff', `<span style="color:#374151;">${escHtml(ticket.title)}</span>`],
          ['Status', statusBadge(ticket.status)],
      ])}`;

@@ -611,19 +611,19 @@ async function sendStaffCommentNotification(ticket, comment) {
        const content = `
      <h2 style="margin:0 0 8px;font-size:21px;font-weight:800;color:#111827;font-family:Inter,Helvetica,Arial,sans-serif;">Neue Antwort im Ticket</h2>
      <p style="margin:0 0 20px;font-size:14px;color:#6b7280;line-height:1.7;font-family:Inter,Helvetica,Arial,sans-serif;">
-        <strong>${requesterName}</strong> hat auf Ticket <strong style="color:#0d9488;">${ticket.ticket_number}</strong> geantwortet.
+        <strong>${escHtml(requesterName)}</strong> hat auf Ticket <strong style="color:#0d9488;">${escHtml(ticket.ticket_number)}</strong> geantwortet.
      </p>
      <table width="100%" cellpadding="0" cellspacing="0" border="0" style="width:100%;border:1px solid #e5e7eb;border-radius:10px;overflow:hidden;margin-bottom:22px;">
        <tr><td bgcolor="#f8fafc" style="background-color:#f8fafc;padding:10px 16px;border-bottom:1px solid #e5e7eb;">
-          <span style="font-size:13px;font-weight:700;color:#111827;font-family:Inter,Helvetica,Arial,sans-serif;">${requesterName}</span>
+          <span style="font-size:13px;font-weight:700;color:#111827;font-family:Inter,Helvetica,Arial,sans-serif;">${escHtml(requesterName)}</span>
        </td></tr>
        <tr><td bgcolor="#ffffff" style="background-color:#ffffff;padding:16px;font-size:14px;color:#1f2937;line-height:1.75;white-space:pre-line;font-family:Inter,Helvetica,Arial,sans-serif;">
-          ${comment.comment.replace(/</g, '&lt;').replace(/>/g, '&gt;')}
+          ${escHtml(comment.comment)}
        </td></tr>
      </table>
      ${infoCard([
-          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${ticket.ticket_number}</strong>`],
-          ['Betreff', `<span style="color:#374151;">${ticket.title}</span>`],
+          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${escHtml(ticket.ticket_number)}</strong>`],
+          ['Betreff', `<span style="color:#374151;">${escHtml(ticket.title)}</span>`],
          ['Status', statusBadge(ticket.status)],
      ])}`;

@@ -660,10 +660,10 @@ async function sendStaffTicketCreatedNotification(ticket) {
        const content = `
      <h2 style="margin:0 0 8px;font-size:21px;font-weight:800;color:#111827;font-family:Inter,Helvetica,Arial,sans-serif;">Neues Ticket eingegangen</h2>
      ${infoCard([
-          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${ticket.ticket_number}</strong>`],
-          ['Betreff', `<strong style="color:#111827;">${ticket.title}</strong>`],
-          ['Von', `<span style="color:#374151;">${ticket.requester_name || ''}${ticket.requester_email ? ` &lt;${ticket.requester_email}&gt;` : ''}</span>`],
-          ['Kategorie', `<span style="color:#374151;">${ticket.category || '—'}</span>`],
+          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${escHtml(ticket.ticket_number)}</strong>`],
+          ['Betreff', `<strong style="color:#111827;">${escHtml(ticket.title)}</strong>`],
+          ['Von', `<span style="color:#374151;">${escHtml(ticket.requester_name || '')}${ticket.requester_email ? ` &lt;${escHtml(ticket.requester_email)}&gt;` : ''}</span>`],
+          ['Kategorie', `<span style="color:#374151;">${escHtml(ticket.category || '—')}</span>`],
          ['Priorität', priorityBadge(ticket.priority)],
      ])}`;

@@ -735,8 +735,8 @@ async function sendStatusChangeNotification(ticket, oldStatus, newStatus) {
      ${statusChangeVisual}

      ${infoCard([
-          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${ticket.ticket_number}</strong>`],
-          ['Betreff', `<span style="color:#374151;">${ticket.title}</span>`],
+          ['Ticket-Nr.', `<strong style="font-family:'Courier New',Courier,monospace;color:#0d9488;font-size:13px;">${escHtml(ticket.ticket_number)}</strong>`],
+          ['Betreff', `<span style="color:#374151;">${escHtml(ticket.title)}</span>`],
          ['Priorität', priorityBadge(ticket.priority)],
      ])}

@@ -1032,10 +1032,10 @@ async function sendEscalationEmail(ticket) {
        ${introHtml}
    </p>
    <table width="100%" cellpadding="12" style="background:#fff8f8;border:1px solid #fca5a5;border-radius:8px;margin:0 0 16px;">
-      <tr><td><strong>Ticket:</strong> ${ticket.ticket_number}</td></tr>
-      <tr><td><strong>Titel:</strong> ${ticket.title}</td></tr>
+      <tr><td><strong>Ticket:</strong> ${escHtml(ticket.ticket_number)}</td></tr>
+      <tr><td><strong>Titel:</strong> ${escHtml(ticket.title)}</td></tr>
      <tr><td><strong>Priorität:</strong> ${priorityBadge(ticket.priority)}</td></tr>
-      <tr><td><strong>Ersteller:</strong> ${ticket.requester_name || ticket.requester_email || 'Unbekannt'}</td></tr>
+      <tr><td><strong>Ersteller:</strong> ${escHtml(ticket.requester_name || ticket.requester_email || 'Unbekannt')}</td></tr>
      <tr><td><strong>Erstellt:</strong> ${new Date(ticket.created_at + 'Z').toLocaleString('de-DE')}</td></tr>
    </table>`;

--- a/backend/src/utils/authCookie.js
+++ b/backend/src/utils/authCookie.js
@@ -0,0 +1,20 @@
+const COOKIE_NAME = 'token';
+const isProd = process.env.NODE_ENV === 'production';
+
+// httpOnly-Cookie statt Token in JS-lesbarem localStorage — verhindert dass ein XSS-Treffer
+// das Session-Token einfach per document.cookie/localStorage ausliest.
+function setAuthCookie(res, token, maxAgeMs = 8 * 60 * 60 * 1000) {
+    res.cookie(COOKIE_NAME, token, {
+        httpOnly: true,
+        secure: isProd,
+        sameSite: 'lax',
+        maxAge: maxAgeMs,
+        path: '/',
+    });
+}
+
+function clearAuthCookie(res) {
+    res.clearCookie(COOKIE_NAME, { httpOnly: true, secure: isProd, sameSite: 'lax', path: '/' });
+}
+
+module.exports = { setAuthCookie, clearAuthCookie, COOKIE_NAME };
--- a/backend/src/utils/crypto.js
+++ b/backend/src/utils/crypto.js
@@ -0,0 +1,34 @@
+const crypto = require('crypto');
+
+const ALGORITHM = 'aes-256-gcm';
+
+function getKey() {
+    const secret = process.env.ENCRYPTION_KEY || process.env.JWT_SECRET || 'itnexus-fallback-key';
+    return crypto.createHash('sha256').update(secret).digest();
+}
+
+function encrypt(plainText) {
+    if (plainText === null || plainText === undefined || plainText === '') return null;
+    const iv = crypto.randomBytes(12);
+    const cipher = crypto.createCipheriv(ALGORITHM, getKey(), iv);
+    const encrypted = Buffer.concat([cipher.update(String(plainText), 'utf8'), cipher.final()]);
+    const authTag = cipher.getAuthTag();
+    return `${iv.toString('base64')}:${authTag.toString('base64')}:${encrypted.toString('base64')}`;
+}
+
+function decrypt(cipherText) {
+    if (!cipherText) return null;
+    const parts = cipherText.split(':');
+    if (parts.length !== 3) return cipherText; // unverschlüsselter Altbestand
+    try {
+        const [ivB64, authTagB64, dataB64] = parts;
+        const decipher = crypto.createDecipheriv(ALGORITHM, getKey(), Buffer.from(ivB64, 'base64'));
+        decipher.setAuthTag(Buffer.from(authTagB64, 'base64'));
+        const decrypted = Buffer.concat([decipher.update(Buffer.from(dataB64, 'base64')), decipher.final()]);
+        return decrypted.toString('utf8');
+    } catch {
+        return null;
+    }
+}
+
+module.exports = { encrypt, decrypt };
--- a/backend/src/utils/ssrfGuard.js
+++ b/backend/src/utils/ssrfGuard.js
@@ -0,0 +1,47 @@
+const dns = require('dns').promises;
+
+function isPrivateIp(ip) {
+    if (ip.includes(':')) {
+        // IPv6: loopback, link-local, unique-local
+        return ip === '::1' || /^fe80:/i.test(ip) || /^fc[0-9a-f]{2}:/i.test(ip) || /^fd[0-9a-f]{2}:/i.test(ip);
+    }
+    const parts = ip.split('.').map(Number);
+    if (parts.length !== 4 || parts.some(p => Number.isNaN(p))) return true; // unparsable → sicherheitshalber blocken
+    const [a, b] = parts;
+    if (a === 127) return true;            // Loopback
+    if (a === 10) return true;             // Private
+    if (a === 172 && b >= 16 && b <= 31) return true; // Private
+    if (a === 192 && b === 168) return true;          // Private
+    if (a === 169 && b === 254) return true;          // Link-local
+    if (a === 0) return true;              // "this network"
+    return false;
+}
+
+// Wirft, falls die URL auf interne/private Adressen oder Loopback zeigt — verhindert SSRF
+// über den Knowledge-Base-URL-Import (Server würde sonst beliebige interne Endpunkte abrufen).
+async function assertPublicUrl(urlString) {
+    const parsed = new URL(urlString);
+    if (!['http:', 'https:'].includes(parsed.protocol)) {
+        throw new Error('Nur HTTP/HTTPS URLs erlaubt');
+    }
+    const hostname = parsed.hostname;
+    if (hostname === 'localhost' || hostname.endsWith('.local')) {
+        throw new Error('Interne/lokale Adressen sind nicht erlaubt');
+    }
+
+    let addresses;
+    try {
+        addresses = await dns.lookup(hostname, { all: true });
+    } catch {
+        throw new Error('Hostname konnte nicht aufgelöst werden');
+    }
+
+    for (const { address } of addresses) {
+        if (isPrivateIp(address)) {
+            throw new Error('Interne/private Adressen sind nicht erlaubt');
+        }
+    }
+    return parsed;
+}
+
+module.exports = { assertPublicUrl, isPrivateIp };
--- a/backend/src/ws/shellServer.js
+++ b/backend/src/ws/shellServer.js
@@ -90,20 +90,28 @@ function handleAgent(ws, url) {
    });
 }

+// Token kommt NICHT mehr als URL-Query-Param (landet sonst im Klartext in nginx-Access-Logs),
+// sondern als erste WS-Message ({type:'auth',token}) — erst danach wird die Verbindung freigeschaltet.
 function handleBrowser(ws, url) {
-    const token = url.searchParams.get('token');
-    try {
-        jwt.verify(token, process.env.JWT_SECRET);
-    } catch {
-        ws.close(1008, 'unauthorized');
-        return;
-    }
-
    const agentId = parseInt(url.searchParams.get('agentId'));
    if (!agentId) { ws.close(1008, 'agentId required'); return; }

-    browserSockets.set(agentId, ws);
+    let authenticated = false;
+    const authTimer = setTimeout(() => { if (!authenticated) ws.close(1008, 'auth timeout'); }, 5000);

+    ws.on('message', (data) => {
+        if (!authenticated) {
+            clearTimeout(authTimer);
+            let decoded;
+            try {
+                const msg = JSON.parse(data.toString());
+                if (msg.type !== 'auth') throw new Error();
+                decoded = jwt.verify(msg.token, process.env.JWT_SECRET);
+            } catch { ws.close(1008, 'unauthorized'); return; }
+            if (!['admin', 'super_admin'].includes(decoded.role)) { ws.close(1008, 'forbidden'); return; }
+            authenticated = true;
+
+            browserSockets.set(agentId, ws);
            const aws = agentSockets.get(agentId);
            if (aws?.readyState === WebSocket.OPEN) {
                aws.send(JSON.stringify({ type: 'start_shell' }));
@@ -111,8 +119,9 @@ function handleBrowser(ws, url) {
            } else {
                ws.send('\x1b[33m[Warte auf Agent-Verbindung...]\x1b[0m\r\n');
            }
+            return;
+        }

-    ws.on('message', (data) => {
        const aws = agentSockets.get(agentId);
        if (!aws || aws.readyState !== WebSocket.OPEN) return;
        // RTC-Signaling (offer/answer/ice) → transparent weiterleiten
@@ -164,18 +173,30 @@ function handleRdpAgent(ws, url) {
 }

 function handleRdpBrowser(ws, url) {
-    const token = url.searchParams.get('token');
-    try { jwt.verify(token, process.env.JWT_SECRET); }
-    catch { ws.close(1008, 'unauthorized'); return; }
-
    const agentId = parseInt(url.searchParams.get('agentId'));
    if (!agentId) { ws.close(1008, 'agentId required'); return; }

+    let authenticated = false;
+    const authTimer = setTimeout(() => { if (!authenticated) ws.close(1008, 'auth timeout'); }, 5000);
+
+    ws.on('message', (data) => {
+        if (!authenticated) {
+            clearTimeout(authTimer);
+            let decoded;
+            try {
+                const msg = JSON.parse(data.toString());
+                if (msg.type !== 'auth') throw new Error();
+                decoded = jwt.verify(msg.token, process.env.JWT_SECRET);
+            } catch { ws.close(1008, 'unauthorized'); return; }
+            if (!['admin', 'super_admin'].includes(decoded.role)) { ws.close(1008, 'forbidden'); return; }
+            authenticated = true;
+
            const oldBws = rdpBrowserSockets.get(agentId);
            if (oldBws?.readyState === WebSocket.OPEN) oldBws.close();
            rdpBrowserSockets.set(agentId, ws);
+            return;
+        }

-    ws.on('message', (data) => {
        const aws = rdpAgentSockets.get(agentId);
        if (aws?.readyState === WebSocket.OPEN) aws.send(data.toString());
    });
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -9,6 +9,7 @@
      "version": "1.0.0",
      "dependencies": {
        "axios": "^1.6.5",
+        "dompurify": "^3.4.11",
        "html5-qrcode": "^2.3.8",
        "marked": "^17.0.4",
        "react": "^18.2.0",
@@ -3958,7 +3959,7 @@
      "version": "2.0.7",
      "resolved": "https://registry.npmjs.org/@types/trusted-types/-/trusted-types-2.0.7.tgz",
      "integrity": "sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw==",
-      "dev": true,
+      "devOptional": true,
      "license": "MIT"
    },
    "node_modules/@types/ws": {
@@ -7074,6 +7075,15 @@
        "url": "https://github.com/fb55/domhandler?sponsor=1"
      }
    },
+    "node_modules/dompurify": {
+      "version": "3.4.11",
+      "resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.4.11.tgz",
+      "integrity": "sha512-zhlUV12GsaRzMsf9q5M254YhA4+VuF0fG+QFqu6aYpoGlKtz+w8//jBcGVYBgQkR5GHjUomejY84AV+/uPbWdw==",
+      "license": "(MPL-2.0 OR Apache-2.0)",
+      "optionalDependencies": {
+        "@types/trusted-types": "^2.0.7"
+      }
+    },
    "node_modules/domutils": {
      "version": "2.8.0",
      "resolved": "https://registry.npmjs.org/domutils/-/domutils-2.8.0.tgz",
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -5,6 +5,7 @@
  "private": true,
  "dependencies": {
    "axios": "^1.6.5",
+    "dompurify": "^3.4.11",
    "html5-qrcode": "^2.3.8",
    "marked": "^17.0.4",
    "react": "^18.2.0",
--- a/frontend/public/share-tool.html
+++ b/frontend/public/share-tool.html
@@ -1234,21 +1234,16 @@ button, input, textarea, select { font: inherit; color: inherit; }
  let shares = [];
  let demoMode = false;

-  /* ---------- Auth token ---------- */
-  const TOKEN_KEY = "token";
-  const getToken = () => localStorage.getItem(TOKEN_KEY);
-  const setToken = (t) => localStorage.setItem(TOKEN_KEY, t);
-  const clearToken = () => localStorage.removeItem(TOKEN_KEY);
+  /* ---------- Auth (httpOnly-Cookie, kein Token in localStorage/URL) ---------- */
+  let demoModeFlag = false;

  /* ---------- Fetch helper ---------- */
  async function api(path, opts = {}) {
    const headers = new Headers(opts.headers || {});
-    const tk = getToken();
-    if (tk) headers.set("Authorization", "Bearer " + tk);
    if (opts.body && !(opts.body instanceof FormData) && !headers.has("Content-Type")) {
      headers.set("Content-Type", "application/json");
    }
-    const res = await fetch(path, { ...opts, headers });
+    const res = await fetch(path, { ...opts, headers, credentials: "include" });
    if (!res.ok) {
      const err = new Error("HTTP " + res.status);
      err.status = res.status;
@@ -1259,19 +1254,6 @@ button, input, textarea, select { font: inherit; color: inherit; }
    return ct.includes("application/json") ? res.json() : res.text();
  }

-  /* ---------- Capture ?token= from URL ---------- */
-  function captureUrlToken() {
-    const params = new URLSearchParams(location.search);
-    const t = params.get("token");
-    if (t) {
-      setToken(t);
-      params.delete("token");
-      const qs = params.toString();
-      const newUrl = location.pathname + (qs ? "?" + qs : "") + location.hash;
-      history.replaceState(null, "", newUrl);
-    }
-  }
-
  /* ---------- Theme toggle ---------- */
  (function initTheme() {
    const KEY = "cereda-theme";
@@ -1290,17 +1272,12 @@ button, input, textarea, select { font: inherit; color: inherit; }

  /* ---------- Init ---------- */
  async function init() {
-    captureUrlToken();
-    const tk = getToken();
-    if (!tk) return showLogin();
-
    try {
      const me = await api("/api/auth/me");
      showApp(me);
      await loadShares();
    } catch (e) {
      if (e.status === 401 || e.status === 403) {
-        clearToken();
        showLogin();
      } else {
        enterDemoMode();
@@ -1311,7 +1288,7 @@ button, input, textarea, select { font: inherit; color: inherit; }
  /* ---------- Demo fallback ---------- */
  function enterDemoMode() {
    demoMode = true;
-    setToken("demo-token");
+    demoModeFlag = true;
    showApp({ username: "m.schmidt", display_name: "Marco Schmidt" });
    demoBadge.classList.add("on");
    shares = seedShares();
@@ -1391,12 +1368,11 @@ button, input, textarea, select { font: inherit; color: inherit; }
        method: "POST",
        body: JSON.stringify({ username, password })
      });
-      if (res && res.token) {
-        setToken(res.token);
+      if (res && res.status === "success") {
        const me = await api("/api/auth/me").catch(() => null);
        showApp(me || { username });
        await loadShares();
-      } else throw new Error("No token in response.");
+      } else throw new Error("Login fehlgeschlagen.");
    } catch (err) {
      if (err.status === 401 || err.status === 403) {
        // Real auth rejection — show the error
@@ -1413,7 +1389,7 @@ button, input, textarea, select { font: inherit; color: inherit; }

  /* ---------- Logout ---------- */
  logoutBtn.addEventListener("click", () => {
-    clearToken();
+    if (!demoModeFlag) { api("/api/auth/logout", { method: "POST" }).catch(() => {}); }
    shares = [];
    pickedFile = null;
    demoMode = false;
@@ -1593,7 +1569,7 @@ button, input, textarea, select { font: inherit; color: inherit; }
      const list = await api("/api/shares");
      shares = Array.isArray(list) ? list : (list?.shares || []);
    } catch (e) {
-      if (e.status === 401) { clearToken(); showLogin(); return; }
+      if (e.status === 401) { showLogin(); return; }
      // 403 = not admin, just show empty list — user can still create shares
      shares = [];
    }
--- a/frontend/src/components/common/AiChatWidget.jsx
+++ b/frontend/src/components/common/AiChatWidget.jsx
@@ -2,17 +2,7 @@ import React, { useState, useRef, useEffect } from 'react';
 import { useLocation } from 'react-router-dom';
 import { useAuth } from '../../context/AuthContext';
 import aiService from '../../services/aiService';
-import { marked } from 'marked';
-
-marked.use({ breaks: true, gfm: true });
-const renderMd = (text) => {
-    try {
-        const html = marked.parse(String(text || ''), { async: false });
-        return { __html: typeof html === 'string' ? html : String(html) };
-    } catch {
-        return { __html: String(text || '').replace(/\n/g, '<br>') };
-    }
-};
+import { renderMd } from '../../utils/sanitizeMarkdown';

 const STAFF_ROLES = ['super_admin', 'admin', 'support', 'bearbeiter'];

--- a/frontend/src/components/common/RemoteDesktopPanel.jsx
+++ b/frontend/src/components/common/RemoteDesktopPanel.jsx
@@ -20,9 +20,8 @@ export default function RemoteDesktopPanel({ agentId, agentHostname, autoConnect
    const connectedRef = useRef(false);

    const getWsUrl = () => {
-        const token = localStorage.getItem('token');
        const proto = window.location.protocol === 'https:' ? 'wss' : 'ws';
-        return `${proto}://${window.location.host}/ws?type=rdp&agentId=${agentId}&token=${token}`;
+        return `${proto}://${window.location.host}/ws?type=rdp&agentId=${agentId}`;
    };

    const connect = (screen = screenIdx) => {
@@ -33,6 +32,7 @@ export default function RemoteDesktopPanel({ agentId, agentHostname, autoConnect

        connectedRef.current = false;
        ws.onopen = () => {
+            ws.send(JSON.stringify({ type: 'auth', token: localStorage.getItem('token') }));
            ws.send(JSON.stringify({ type: 'rdp_start', screen }));
        };

--- a/frontend/src/pages/AgentDetailPage.jsx
+++ b/frontend/src/pages/AgentDetailPage.jsx
@@ -177,10 +177,9 @@ function RemoteShell({ agentId, agentHostname }) {
    const inputRef = useRef(null);

    const getWsUrl = () => {
-        const token = localStorage.getItem('token');
        const proto = window.location.protocol === 'https:' ? 'wss' : 'ws';
        const host = window.location.host;
-        return `${proto}://${host}/ws?type=shell&agentId=${agentId}&token=${token}`;
+        return `${proto}://${host}/ws?type=shell&agentId=${agentId}`;
    };

    const connect = () => {
@@ -191,7 +190,10 @@ function RemoteShell({ agentId, agentHostname }) {
        const ws = new WebSocket(getWsUrl());
        wsRef.current = ws;

-        ws.onopen = () => setStatus('connected');
+        ws.onopen = () => {
+            ws.send(JSON.stringify({ type: 'auth', token: localStorage.getItem('token') }));
+            setStatus('connected');
+        };

        ws.onmessage = (e) => {
            setOutput(prev => prev + stripAnsi(e.data));
@@ -766,7 +768,7 @@ export default function AgentDetailPage() {
            </div>

            {/* ── REMOTE TOOLS ─────────────────────────────────────────────────── */}
-            {(isSuperAdmin || isAdmin) && (
+            {(isSuperAdmin() || isAdmin()) && (
                <div style={{ marginTop: 24 }}>
                    <div style={{ display: 'flex', gap: 4, marginBottom: 0, borderBottom: '1px solid var(--border-color)' }}>
                        {[
@@ -790,10 +792,6 @@ export default function AgentDetailPage() {
                    {shellTab === 'rdp' && <RemoteDesktop agentId={agent.id} agentHostname={agent.hostname} />}
                </div>
            )}
-            {!isSuperAdmin && !isAdmin && (
-                <RemoteShell agentId={agent.id} agentHostname={agent.hostname} />
-            )}
-
            {/* ── ANKÜNDIGUNG MODAL ────────────────────────────────────────────── */}
            {showAnnModal && (
                <div style={{ position: 'fixed', inset: 0, background: 'rgba(0,0,0,.6)', zIndex: 1000, display: 'flex', alignItems: 'center', justifyContent: 'center' }}
--- a/frontend/src/pages/AiPage.jsx
+++ b/frontend/src/pages/AiPage.jsx
@@ -2,10 +2,7 @@ import React, { useState, useEffect, useRef } from 'react';
 import { useAuth } from '../context/AuthContext';
 import aiService from '../services/aiService';
 import { toast } from 'react-toastify';
-import { Marked } from 'marked';
-
-const marked = new Marked({ breaks: true, gfm: true });
-const renderMd = (text) => ({ __html: marked.parse(text) });
+import { renderMd } from '../utils/sanitizeMarkdown';

 const WELCOME_MSG = {
    role: 'assistant',
--- a/frontend/src/pages/DocsPage.jsx
+++ b/frontend/src/pages/DocsPage.jsx
@@ -1,5 +1,6 @@
 import React, { useState, useEffect } from 'react';
 import { Marked } from 'marked';
+import { sanitizeHtml } from '../utils/sanitizeMarkdown';

 const marked = new Marked({ breaks: true, gfm: true });

@@ -42,10 +43,11 @@ export default function DocsPage() {
        }
        // Add IDs to headings for anchor links
        const html = marked.parse(text);
-        return html.replace(/<h([23])>(.*?)<\/h\1>/g, (_, level, heading) => {
+        const withIds = html.replace(/<h([23])>(.*?)<\/h\1>/g, (_, level, heading) => {
            const id = slugify(heading.replace(/<[^>]+>/g, ''));
            return `<h${level} id="${id}">${heading}</h${level}>`;
        });
+        return sanitizeHtml(withIds);
    };

    if (loading) return (
--- a/frontend/src/pages/FidoKeysPage.jsx
+++ b/frontend/src/pages/FidoKeysPage.jsx
@@ -25,8 +25,17 @@ const FidoKeysPage = () => {
        serial_number: '',
        status: 'aktiv',
        description: '',
+        pin: '',
        assigned_to_user_id: '',
    });
+    const [revealedPins, setRevealedPins] = useState({});
+
+    const togglePinReveal = (id) => {
+        setRevealedPins(prev => ({ ...prev, [id]: !prev[id] }));
+        if (!revealedPins[id]) {
+            setTimeout(() => setRevealedPins(prev => ({ ...prev, [id]: false })), 8000);
+        }
+    };

    useEffect(() => {
        loadKeys();
@@ -69,7 +78,7 @@ const FidoKeysPage = () => {

    const handleCreate = () => {
        setEditingKey(null);
-        setFormData({ name: '', serial_number: '', status: 'aktiv', description: '', assigned_to_user_id: '' });
+        setFormData({ name: '', serial_number: '', status: 'aktiv', description: '', pin: '', assigned_to_user_id: '' });
        setShowModal(true);
    };

@@ -80,6 +89,7 @@ const FidoKeysPage = () => {
            serial_number: key.serial_number,
            status: key.status,
            description: key.description || '',
+            pin: key.pin || '',
            assigned_to_user_id: key.assigned_to_user_id || '',
        });
        setShowModal(true);
@@ -181,6 +191,7 @@ const FidoKeysPage = () => {
                                <th>Seriennummer</th>
                                <th>Status</th>
                                <th>Zugewiesen an</th>
+                                <th>PIN</th>
                                <th>Beschreibung</th>
                                <th>Erstellt von</th>
                                <th>Aktionen</th>
@@ -189,13 +200,20 @@ const FidoKeysPage = () => {
                        <tbody>
                            {filteredKeys.length === 0 ? (
                                <tr>
-                                    <td colSpan="7" className="text-center">Keine FIDO-Keys gefunden</td>
+                                    <td colSpan="8" className="text-center">Keine FIDO-Keys gefunden</td>
                                </tr>
                            ) : (
                                filteredKeys.map((key) => (
                                    <tr key={key.id}>
-                                        <td>{key.name}</td>
-                                        <td><code style={{fontSize:12}}>{key.serial_number}</code></td>
+                                        <td>
+                                            <div style={{display:'flex',alignItems:'center',gap:10,fontWeight:600}}>
+                                                <div style={{width:32,height:32,borderRadius:8,background:'rgba(63,163,163,0.12)',display:'flex',alignItems:'center',justifyContent:'center',flexShrink:0}}>
+                                                    <svg viewBox="0 0 24 24" fill="none" stroke="var(--cereda-primary)" strokeWidth="2" width="16" height="16"><circle cx="8" cy="8" r="5"/><path d="M10.5 12.5 19 21M16 16l2-2M19 19l2-2"/></svg>
+                                                </div>
+                                                {key.name}
+                                            </div>
+                                        </td>
+                                        <td><span style={{fontFamily:'Consolas,monospace',background:'var(--bg-tertiary)',border:'1px solid var(--border-color)',borderRadius:6,padding:'3px 8px',fontSize:12,color:'var(--text-muted)'}}>{key.serial_number}</span></td>
                                        <td>
                                            <span className={`status-badge status-${key.status}`}>{key.status}</span>
                                        </td>
@@ -218,20 +236,50 @@ const FidoKeysPage = () => {
                                                <span style={{color:'var(--text-muted)',fontSize:12}}>— nicht zugewiesen</span>
                                            )}
                                        </td>
+                                        <td>
+                                            {key.pin ? (
+                                                <div style={{display:'flex',alignItems:'center',gap:8}}>
+                                                    <span style={{fontFamily:'Consolas,monospace',background:'var(--bg-tertiary)',border:'1px solid var(--border-color)',borderRadius:6,padding:'3px 10px',fontSize:13,letterSpacing:'0.15em',minWidth:64,textAlign:'center',display:'inline-block'}}>
+                                                        {revealedPins[key.id] ? key.pin : '••••••'}
+                                                    </span>
+                                                    <button
+                                                        onClick={() => togglePinReveal(key.id)}
+                                                        title={revealedPins[key.id] ? 'PIN verbergen' : 'PIN anzeigen'}
+                                                        style={{background:'none',border:'none',cursor:'pointer',color:'var(--text-muted)',padding:2,display:'flex',alignItems:'center'}}
+                                                    >
+                                                        {revealedPins[key.id] ? (
+                                                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="16" height="16"><path d="M17.94 17.94A10.07 10.07 0 0 1 12 20c-7 0-11-7-11-7a18.45 18.45 0 0 1 5.06-5.94M9.9 4.24A9.12 9.12 0 0 1 12 4c7 0 11 7 11 7a18.5 18.5 0 0 1-2.16 3.19M14.12 14.12a3 3 0 1 1-4.24-4.24"/><path d="M1 1l22 22"/></svg>
+                                                        ) : (
+                                                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="16" height="16"><path d="M1 12s4-7 11-7 11 7 11 7-4 7-11 7-11-7-11-7Z"/><circle cx="12" cy="12" r="3"/></svg>
+                                                        )}
+                                                    </button>
+                                                </div>
+                                            ) : (
+                                                <span style={{color:'var(--text-muted)',fontSize:12}}>— keine PIN</span>
+                                            )}
+                                        </td>
                                        <td>{key.description || '-'}</td>
                                        <td>{key.created_by_username}</td>
                                        <td>
                                            <div className="table-actions">
                                                {canModifyFidoKeys() && (
                                                    <>
-                                                        <button onClick={() => handleEdit(key)} className="btn btn-primary btn-small">Bearbeiten</button>
-                                                        <button onClick={() => handleStatusToggle(key)} className="btn btn-secondary btn-small">
-                                                            {key.status === 'aktiv' ? 'Deaktivieren' : 'Aktivieren'}
+                                                        <button onClick={() => handleEdit(key)} title="Bearbeiten" className="btn btn-secondary btn-small" style={{width:32,padding:0,display:'flex',alignItems:'center',justifyContent:'center'}}>
+                                                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="14" height="14"><path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"/><path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4Z"/></svg>
+                                                        </button>
+                                                        <button onClick={() => handleStatusToggle(key)} title={key.status === 'aktiv' ? 'Deaktivieren' : 'Aktivieren'} className="btn btn-secondary btn-small" style={{width:32,padding:0,display:'flex',alignItems:'center',justifyContent:'center'}}>
+                                                            {key.status === 'aktiv' ? (
+                                                                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="14" height="14"><rect x="6" y="4" width="4" height="16"/><rect x="14" y="4" width="4" height="16"/></svg>
+                                                            ) : (
+                                                                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="14" height="14"><path d="M5 3l16 9-16 9V3z"/></svg>
+                                                            )}
                                                        </button>
                                                    </>
                                                )}
                                                {isAdmin() && (
-                                                    <button onClick={() => handleDelete(key.id)} className="btn btn-danger btn-small">Löschen</button>
+                                                    <button onClick={() => handleDelete(key.id)} title="Löschen" className="btn btn-danger btn-small" style={{width:32,padding:0,display:'flex',alignItems:'center',justifyContent:'center'}}>
+                                                        <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="14" height="14"><path d="M3 6h18"/><path d="M8 6V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2m3 0-1 14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2L4 6"/></svg>
+                                                    </button>
                                                )}
                                            </div>
                                        </td>
@@ -261,6 +309,20 @@ const FidoKeysPage = () => {
                                    <input type="text" className="form-input" value={formData.serial_number} onChange={(e) => setFormData({ ...formData, serial_number: e.target.value })} required />
                                </div>

+                                <div className="form-group">
+                                    <label className="form-label">PIN</label>
+                                    <input
+                                        type="text"
+                                        className="form-input"
+                                        maxLength={6}
+                                        pattern="[0-9]{6}"
+                                        placeholder="6-stellige PIN"
+                                        value={formData.pin}
+                                        onChange={(e) => setFormData({ ...formData, pin: e.target.value.replace(/\D/g, '').slice(0, 6) })}
+                                        style={{fontFamily:'Consolas,monospace',letterSpacing:'0.2em'}}
+                                    />
+                                </div>
+
                                <div className="form-group">
                                    <label className="form-label">Status*</label>
                                    <select className="form-select" value={formData.status} onChange={(e) => setFormData({ ...formData, status: e.target.value })} required>
--- a/frontend/src/pages/KnowledgeBasePage.jsx
+++ b/frontend/src/pages/KnowledgeBasePage.jsx
@@ -4,9 +4,7 @@ import { useAuth } from '../context/AuthContext';
 import aiService from '../services/aiService';
 import ticketService from '../services/ticketService';
 import { toast } from 'react-toastify';
-import { Marked } from 'marked';
-const marked = new Marked({ breaks: true, gfm: true });
-const renderMd = (text) => ({ __html: marked.parse(text || '') });
+import { renderMd } from '../utils/sanitizeMarkdown';

 const CATEGORIES = ['Allgemein', 'Software', 'Hardware', 'Netzwerk', 'SelectLine', 'Sonstiges'];
 const CAT_COLOR = { Software: '#6366f1', Hardware: '#f59e0b', SelectLine: '#10b981', Netzwerk: '#3b82f6', Allgemein: '#64748b', Sonstiges: '#8b5cf6' };
--- a/frontend/src/pages/PatchManagementPage.jsx
+++ b/frontend/src/pages/PatchManagementPage.jsx
@@ -5,7 +5,7 @@ import { useAuth } from '../context/AuthContext';

 const ANN_TYPES = { maintenance: { icon: '🔧', label: 'Wartung', color: '#f59e0b' }, warning: { icon: '⚠️', label: 'Warnung', color: '#ef4444' }, info: { icon: 'ℹ️', label: 'Info', color: '#6366f1' } };

-const LATEST_AGENT_VERSION = '2.6.0';
+const LATEST_AGENT_VERSION = '2.7.0';
 const SEVERITY_LABELS = { critical: 'Kritisch', important: 'Wichtig', moderate: 'Moderat', low: 'Niedrig', all: 'Alle' };
 const SEVERITY_COLORS = { critical: '#EF4444', important: '#F59E0B', moderate: '#3B82F6', low: '#6B7280', all: '#0D9488' };
 const COMMAND_LABELS = { check_updates: '🔍 Update-Scan', install_updates: '⬇️ Installation', reboot: '🔄 Neustart', upgrade_win11: '🪟 Win 11 Upgrade', update_agent: '⬆️ Agent-Update' };
--- a/frontend/src/pages/TVDashboardPage.jsx
+++ b/frontend/src/pages/TVDashboardPage.jsx
@@ -1,7 +1,8 @@
 import React, { useState, useEffect, useCallback, useMemo } from 'react';

 const API = process.env.REACT_APP_API_URL || '/api';
-const apiFetch = (url) => fetch(url).then(r => r.ok ? r.json() : null).catch(() => null);
+const TV_KEY = new URLSearchParams(window.location.search).get('key') || '';
+const apiFetch = (url) => fetch(`${url}${url.includes('?') ? '&' : '?'}key=${encodeURIComponent(TV_KEY)}`).then(r => r.ok ? r.json() : null).catch(() => null);

 /* ── Design tokens ──────────────────────────────────────────── */
 const LIME    = '#7CF53E';
--- a/frontend/src/pages/TicketDetailPage.jsx
+++ b/frontend/src/pages/TicketDetailPage.jsx
@@ -6,17 +6,7 @@ import userService from '../services/userService';
 import assetService from '../services/assetService';
 import LoadingSpinner from '../components/common/LoadingSpinner';
 import { toast } from 'react-toastify';
-import { marked } from 'marked';
-
-marked.use({ breaks: true, gfm: true });
-const renderMd = (text) => {
-    try {
-        const html = marked.parse(String(text || ''), { async: false });
-        return { __html: typeof html === 'string' ? html : String(html) };
-    } catch {
-        return { __html: String(text || '').replace(/\n/g, '<br>') };
-    }
-};
+import { renderMd, sanitizeHtml } from '../utils/sanitizeMarkdown';

 const STATUS_CONFIG = {
    offen:                  { label: 'Offen',                  css: 'status-pending'     },
@@ -549,7 +539,7 @@ const TicketDetailPage = () => {
                                                </div>
                                            );
                                            const boldLine = line.replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>');
-                                            return <div key={i} style={{ minHeight: line ? undefined : '0.5em' }} dangerouslySetInnerHTML={{ __html: boldLine || '&nbsp;' }} />;
+                                            return <div key={i} style={{ minHeight: line ? undefined : '0.5em' }} dangerouslySetInnerHTML={{ __html: sanitizeHtml(boldLine || '&nbsp;') }} />;
                                        })}
                                    </div>
                                ) : (
--- a/frontend/src/pages/UserManagementPage.jsx
+++ b/frontend/src/pages/UserManagementPage.jsx
@@ -712,6 +712,9 @@ const FidoTab = ({ user }) => {
    const [showAssign, setShowAssign] = useState(false);
    const [assignId, setAssignId] = useState('');
    const [saving, setSaving] = useState(false);
+    const [editingId, setEditingId] = useState(null);
+    const [editForm, setEditForm] = useState({ name: '', pin: '', status: 'aktiv' });
+    const [pinRevealed, setPinRevealed] = useState({});

    const loadKeys = () => {
        setLoading(true);
@@ -751,6 +754,29 @@ const FidoTab = ({ user }) => {
        loadKeys();
    };

+    const startEdit = (key) => {
+        setEditingId(key.id);
+        setEditForm({ name: key.name, pin: key.pin || '', status: key.status });
+    };
+
+    const saveEdit = async (key) => {
+        setSaving(true);
+        try {
+            await authFetch(`${API}/fido-keys/${key.id}`, {
+                method: 'PUT',
+                body: JSON.stringify({ ...key, ...editForm }),
+            });
+            setEditingId(null);
+            loadKeys();
+        } catch {
+        } finally { setSaving(false); }
+    };
+
+    const togglePin = (id) => {
+        setPinRevealed(prev => ({ ...prev, [id]: !prev[id] }));
+        if (!pinRevealed[id]) setTimeout(() => setPinRevealed(prev => ({ ...prev, [id]: false })), 8000);
+    };
+
    if (loading) return <div style={{padding:40,textAlign:'center',color:'var(--text-muted)'}}>Lade FIDO-Keys…</div>;

    const hasEnoughKeys = keys.length >= 2;
@@ -760,17 +786,68 @@ const FidoTab = ({ user }) => {
            <div className="bv-fido-hero">
                {keys.map((key, i) => (
                    <div key={key.id} className="bv-fkc-card" style={{position:'relative'}}>
+                        <div style={{position:'absolute',top:8,right:8,display:'flex',gap:6}}>
+                            <button
+                                onClick={() => startEdit(key)}
+                                title="Bearbeiten"
+                                style={{background:'rgba(63,163,163,.12)',border:'1px solid rgba(63,163,163,.3)',color:'var(--cereda-primary)',borderRadius:6,padding:'2px 7px',fontSize:11,cursor:'pointer'}}
+                            >✎ Bearbeiten</button>
                            <button
                                onClick={() => handleUnassign(key)}
                                title="Zuweisung aufheben"
-                            style={{position:'absolute',top:8,right:8,background:'rgba(239,68,68,.12)',border:'1px solid rgba(239,68,68,.3)',color:'#ef4444',borderRadius:6,padding:'2px 7px',fontSize:11,cursor:'pointer'}}
+                                style={{background:'rgba(239,68,68,.12)',border:'1px solid rgba(239,68,68,.3)',color:'#ef4444',borderRadius:6,padding:'2px 7px',fontSize:11,cursor:'pointer'}}
                            >✕ Entfernen</button>
+                        </div>
                        <div className="bv-fkc-header">
                            <div className="bv-fkc-visual"><KeyIcon /></div>
                            <span className="bv-fkc-type-badge">{i === 0 ? 'PRIMÄR' : 'BACKUP'}</span>
                        </div>
+
+                        {editingId === key.id ? (
+                            <div style={{display:'flex',flexDirection:'column',gap:8,marginTop:4}}>
+                                <input
+                                    className="form-input"
+                                    style={{fontSize:13}}
+                                    value={editForm.name}
+                                    onChange={e => setEditForm({ ...editForm, name: e.target.value })}
+                                    placeholder="Name"
+                                />
+                                <input
+                                    className="form-input"
+                                    style={{fontSize:13,fontFamily:'Consolas,monospace',letterSpacing:'0.15em'}}
+                                    value={editForm.pin}
+                                    maxLength={6}
+                                    onChange={e => setEditForm({ ...editForm, pin: e.target.value.replace(/\D/g,'').slice(0,6) })}
+                                    placeholder="PIN (6-stellig)"
+                                />
+                                <select
+                                    className="form-select"
+                                    style={{fontSize:13}}
+                                    value={editForm.status}
+                                    onChange={e => setEditForm({ ...editForm, status: e.target.value })}
+                                >
+                                    <option value="aktiv">Aktiv</option>
+                                    <option value="inaktiv">Inaktiv</option>
+                                </select>
+                                <div style={{display:'flex',gap:8}}>
+                                    <button className="btn btn-primary btn-small" onClick={() => saveEdit(key)} disabled={saving}>{saving ? '…' : 'Speichern'}</button>
+                                    <button className="btn btn-secondary btn-small" onClick={() => setEditingId(null)}>Abbrechen</button>
+                                </div>
+                            </div>
+                        ) : (
+                            <>
                                <div className="bv-fkc-name">{key.name}</div>
                                <div className="bv-fkc-sub">{key.manufacturer || 'Yubico'} · {key.connection_type || 'USB'} · SN {key.serial_number}</div>
+                                {key.pin && (
+                                    <div style={{display:'flex',alignItems:'center',gap:6,marginTop:6}}>
+                                        <span style={{fontFamily:'Consolas,monospace',background:'rgba(0,0,0,.2)',borderRadius:6,padding:'2px 8px',fontSize:12,letterSpacing:'0.15em'}}>
+                                            {pinRevealed[key.id] ? key.pin : '••••••'}
+                                        </span>
+                                        <button onClick={() => togglePin(key.id)} title="PIN anzeigen/verbergen" style={{background:'none',border:'none',cursor:'pointer',color:'inherit',opacity:0.7,padding:0,display:'flex'}}>
+                                            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" width="13" height="13"><path d="M1 12s4-7 11-7 11 7 11 7-4 7-11 7-11-7-11-7Z"/><circle cx="12" cy="12" r="3"/></svg>
+                                        </button>
+                                    </div>
+                                )}
                                <div className="bv-fkc-stats">
                                    <div className="bv-fkc-stat">
                                        <div className="bv-fkcs-v">—</div>
@@ -781,6 +858,8 @@ const FidoTab = ({ user }) => {
                                        <div className="bv-fkcs-l">Letzte Nutzung</div>
                                    </div>
                                </div>
+                            </>
+                        )}
                    </div>
                ))}
                {showAssign ? (
--- a/frontend/src/pages/UserPortalPage.jsx
+++ b/frontend/src/pages/UserPortalPage.jsx
@@ -7,17 +7,7 @@ import fidoKeyService from '../services/fidoKeyService';
 import aiService from '../services/aiService';
 import LoadingSpinner from '../components/common/LoadingSpinner';
 import { toast } from 'react-toastify';
-import { marked } from 'marked';
-
-marked.use({ breaks: true, gfm: true });
-const renderMd = (text) => {
-    try {
-        const html = marked.parse(String(text || ''), { async: false });
-        return { __html: typeof html === 'string' ? html : String(html) };
-    } catch {
-        return { __html: String(text || '').replace(/\n/g, '<br>') };
-    }
-};
+import { renderMd } from '../utils/sanitizeMarkdown';

 /* ── Helpers ────────────────────────────────────────────────────── */

--- a/frontend/src/services/api.js
+++ b/frontend/src/services/api.js
@@ -3,33 +3,16 @@ import axios from 'axios';
 const API_URL = process.env.REACT_APP_API_URL || '/api';

 // Create axios instance
+// Auth läuft über ein httpOnly-Cookie (vom Server gesetzt) — kein Token in JS-lesbarem Storage,
+// damit ein XSS-Treffer das Session-Token nicht einfach auslesen kann.
 const api = axios.create({
    baseURL: API_URL,
+    withCredentials: true,
    headers: {
        'Content-Type': 'application/json',
    },
 });

-// Request interceptor to add token to requests
-api.interceptors.request.use(
-    (config) => {
-        const token = localStorage.getItem('token');
-        if (token) {
-            if (typeof config.headers?.set === 'function') {
-                config.headers.set('Authorization', `Bearer ${token}`);
-            } else if (config.headers) {
-                config.headers['Authorization'] = `Bearer ${token}`;
-            } else {
-                config.headers = { 'Authorization': `Bearer ${token}` };
-            }
-        }
-        return config;
-    },
-    (error) => {
-        return Promise.reject(error);
-    }
-);
-
 // Response interceptor to handle errors globally
 api.interceptors.response.use(
    (response) => {
@@ -39,7 +22,6 @@ api.interceptors.response.use(
        if (error.response) {
            // Handle 401 Unauthorized - token expired or invalid
            if (error.response.status === 401) {
-                localStorage.removeItem('token');
                localStorage.removeItem('user');
                window.location.href = '/login';
            }
--- a/frontend/src/utils/sanitizeMarkdown.js
+++ b/frontend/src/utils/sanitizeMarkdown.js
@@ -0,0 +1,20 @@
+import { Marked } from 'marked';
+import DOMPurify from 'dompurify';
+
+const marked = new Marked({ breaks: true, gfm: true });
+
+// Rendert Markdown zu HTML und entfernt anschließend aktive Inhalte (script, on*-Attribute,
+// javascript:-URLs etc.) — verhindert Stored XSS über KI-Antworten/Kommentare/Knowledge-Base.
+export function renderMd(text) {
+    try {
+        const html = marked.parse(String(text || ''), { async: false });
+        const raw = typeof html === 'string' ? html : String(html);
+        return { __html: DOMPurify.sanitize(raw) };
+    } catch {
+        return { __html: DOMPurify.sanitize(String(text || '').replace(/\n/g, '<br>')) };
+    }
+}
+
+export function sanitizeHtml(html) {
+    return DOMPurify.sanitize(String(html || ''));
+}
--- a/shell-client.js
+++ b/shell-client.js
@@ -0,0 +1,26 @@
+const WebSocket = require('ws');
+const fs = require('fs');
+
+const token = process.argv[2];
+const agentId = process.argv[3];
+const command = process.argv[4].startsWith('@') ? fs.readFileSync(process.argv[4].slice(1), 'utf8') : process.argv[4];
+
+const ws = new WebSocket(`ws://localhost:5000/ws?type=shell&agentId=${agentId}`);
+
+let buffer = '';
+ws.on('open', () => {
+    ws.send(JSON.stringify({ type: 'auth', token }));
+    setTimeout(() => {
+        ws.send(command + '\r\n');
+    }, 1500);
+});
+
+ws.on('message', (data) => {
+    buffer += data.toString();
+});
+
+const waitMs = parseInt(process.argv[5]) || 8000;
+setTimeout(() => {
+    console.log(buffer);
+    process.exit(0);
+}, waitMs);