Executive brief
File Browser, a web-based file management utility, contains a security flaw where the system inadvertently shares sensitive security credentials through its programming interface. When a user or administrator views shared files, the system includes the encrypted password hashes and secret access tokens in the data sent to the browser. This allows an attacker to potentially crack passwords offline or bypass security controls to access protected files without authorization.
Technical details
A sensitive information disclosure vulnerability exists in File Browser due to improper serialization of the 'Link' storage struct. The API handlers for creating and listing shares (POST /api/share and GET /api/shares) use unfiltered json.Marshal on the internal struct, which includes 'password_hash' and 'token' fields. An authenticated user can retrieve these secrets for their own shares, while an administrator can retrieve them for all users' shares. This enables offline brute-force attacks against bcrypt hashes and immediate unauthorized access to protected shares using the leaked bypass tokens. The issue is fixed in version 2.63.17 by removing these fields from the JSON output.
Affected products
- filebrowser filebrowser <= 2.63.16
Timeline
- 2026-07-04: disclosed
- 2026-07-20: advisory
- 2026-07-20: patched: Fixed in version 2.63.17