Описание
phpMyFAQ: Attachment download allowed without dlattachment right (broken access control)
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.
Impact
Unauthorized users can download attachments (confidentiality breach). Depending on content, this may expose sensitive documents.
Пакеты
phpmyfaq/phpmyfaq
<= 4.0.16
4.0.17
thorsten/phpmyfaq
<= 4.0.16
4.0.17
Связанные уязвимости
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