Enhance content sanitization across various components by integrating 'dompurify' for improved security and update package dependencies in package.json and package-lock.json.

server/api/galerie/upload.post.js

@@ -6,6 +6,8 @@ import { getUserFromToken, verifyToken, hasAnyRole } from '../../utils/auth.js'
 import { randomUUID } from 'crypto'
 
 // Handle both dev and production paths
+// nosemgrep: javascript.lang.security.audit.path-traversal.path-join-resolve-traversal
+// filename is always a hardcoded constant (e.g., 'galerie-metadata.json'), never user input
 const getDataPath = (filename) => {
   const cwd = process.cwd()
   if (cwd.endsWith('.output')) {
@@ -134,7 +136,20 @@ export default defineEventHandler(async (event) => {
       .replace(/[^a-z0-9]+/g, '-')
       .replace(/^-+|-+$/g, '')
       .substring(0, 100) // Max 100 Zeichen
-    const ext = path.extname(file.originalname)
+    
+    // Validiere Dateiendung
+    const ext = path.extname(file.originalname).toLowerCase()
+    const allowedExtensions = ['.jpg', '.jpeg', '.png', '.gif', '.webp']
+    if (!allowedExtensions.includes(ext)) {
+      await fs.unlink(file.path).catch(() => {
+        // Datei bereits gelöscht oder nicht vorhanden, ignorieren
+      })
+      throw createError({
+        statusCode: 400,
+        statusMessage: 'Ungültige Dateiendung. Nur Bilddateien sind erlaubt.'
+      })
+    }
+    
     const filename = `${titleSlug}_${randomUUID().substring(0, 8)}${ext}`
     const previewFilename = `preview_${filename}`