Vulnerability Advisory : File Browser has an Authorization Policy Bypass in its Public Share Download Flow with LOW Attack Complexity

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Versions 2.61.0 and below contain a permission enforcement bypass which allows users who are denied download privileges (perm.download = false) but granted share privileges (perm.share = true) to exfiltrate file content by creating public share links. While the direct raw download endpoint (/api/raw/) correctly enforces the download permission, the share creation endpoint only checks Perm.Share, and the public download handler (/api/public/dl/<hash>) serves file content without verifying that the original file owner has download permission. This means any authenticated user with share access can circumvent download restrictions by sharing a file and then retrieving it via the unauthenticated public download URL. The vulnerability undermines data-loss prevention and role-separation policies, as restricted users can publicly distribute files they are explicitly blocked from downloading directly. This issue has been fixed in version 2.62.0.