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Sulu is an open-source PHP content management system built on the Symfony framework. Prior to versions 2.6.25 and 3.0.8, a media move authorization bypass vulnerability (an Insecure Direct Object Reference, or IDOR) existed within its media management component. The core of the issue lies in how the system handles permission checks when a user attempts to move a media file from one collection to another.
The media move endpoint, provided by `MediaController::postTriggerAction` via POST /media/{id}, resolves its permission check based on a `collection` value supplied by the client in the request, rather than verifying the media item’s actual source collection. The `MediaManager::move()` function then reassigns the media to the new collection without re-checking the user’s permissions on the media’s original location.
This design flaw allows an authenticated backend user who has edit rights on at least one collection to exploit the system. By knowing the ID of a target media file located in a restricted collection they do not have access to, the attacker can craft a request that names their own accessible collection as the source. The system accepts this fraudulent source, moves the media out of the restricted collection and into the attacker’s collection, and subsequently grants the attacker the ability to view and download the content.
This vulnerability only affects installations that utilize per-collection (object-level) permissions to restrict access. Exploitation requires an authenticated backend user with edit rights on at least one collection and knowledge of the target media ID. The vulnerability is classified under CWE-639 (Authorization Bypass Through User-Controlled Key) and CWE-863 (Incorrect Authorization).
DailyCVE Form:
Platform: Sulu CMS
Version: < 2.6.25, 3.0.0-alpha1 – < 3.0.8
Vulnerability: IDOR Authorization Bypass
Severity: MEDIUM (CVSS 5.3)
Date: 2026-09-02
Prediction: Already Patched (2026-08-31)
What Undercode Say:
The vulnerability can be exploited over the network, is easy to attack, and requires low-level privileges with no user interaction. The Exploit Prediction Scoring System (EPSS) indicates a very low probability (0.25%) of exploitation in the next 30 days. While limited exploitation activity has been observed, no public exploit is currently available.
Exploit: (Educational Purposes!)
A functional integration test demonstrating the authorization bypass is available in the GitHub Security Advisory (GHSA-h6cx-gjxx-v25c). The core of the exploit involves intercepting the media move request and modifying the `collection` parameter to point to a collection the attacker controls, while the `id` parameter points to a media file in a restricted collection.
Example of a vulnerable request (conceptual)
POST /admin/api/media/{media_id}?action=move
Payload: { "destination": "attacker_collection_id" }
Protection:
The vulnerability is fixed in Sulu versions 2.6.25 and 3.0.8. The patch modifies `MediaManager::move()` to verify edit permissions on both the media’s real source collection (previousCollectionId) and the destination collection before performing the move.
If an immediate upgrade is not possible, the following workarounds are recommended:
– Restrict media edit permissions to trusted users only, preventing untrusted users from triggering the move operation.
– Manually apply the fix by adding an edit permission check on the media’s real source collection and the destination inside MediaManager::move().
Impact:
A successful exploit allows an authenticated attacker to bypass access controls, move restricted media files out of protected collections, and subsequently view or download content they were never authorized to access. This constitutes a clear authorization bypass and an insecure direct object reference, potentially leading to data exfiltration of confidential or restricted content.
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Sources:
Reported By: github.com
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