Ampache issue2: API Shares List

Vulnerability call chain

1.1 Summary

Ampache has a missing authorization vulnerability: API Shares List. The attacker can enumerate and retrieve other users' share secret and public_url values in bulk

• Attack precondition: A low-privileged user has valid API session / API ACL access, the share feature is enabled, and other users have existing share rows
• Security impact: The attacker can enumerate and retrieve other users' share secret and public_url values in bulk

1.2 Exploit path

GET/POST /server/{json,xml}.server.php?action=shares uses Browse type share and returns serialized share rows

1.3 Key code evidence

1. server.php

Evidence location: server.php

3. Root Cause Analysis

Root Cause 1: Missing server-side authorization on the vulnerable operation.

The endpoint accepts user-controlled authorization-sensitive identifiers or fields, but the write/read path does not prove that the current caller may operate on the target object.

Root Cause 2: Missing object-scope or grant-bound validation.

The implementation relies on endpoint access, UI filtering, or object existence checks instead of enforcing target ownership, tenant boundary, role ceiling, or grantable-resource constraints at the service layer.

4. Recommended fix

Use ShareRepository::getIdsByUser($user) for the list source, or add equivalent owner / manager filtering in the share Browse query

5. Verification after fix

• Unauthorized callers receive HTTP 403 or equivalent rejection.
• Out-of-scope target identifiers are rejected before database writes or sensitive reads.
• Role, permission, tenant, organization, ownership, or grant-bound ceilings are enforced server-side.
• Direct HTTP requests are rejected even when front-end controls are hidden.