Directus is a real-time API and App dashboard for managing SQL database content. Prior to 11.17.0, the PATCH /files/{id} endpoint accepts a user-controlled filename_disk parameter. By setting this value to match the storage path of another user's file, an attacker can overwrite that file's content while manipulating metadata fields such as uploaded_by to obscure the tampering. This vulnerability is fixed in 11.17.0.

Affected: npm: directus

## Summary

A broken access control vulnerability was identified in the Directus file management API that allows authenticated users to overwrite files belonging to other users by manipulating the `filename_disk` parameter.

## Details

The `PATCH /files/{id}` endpoint accepts a user-controlled `filename_disk` parameter. By setting this value to match the storage path of another user's file, an attacker can overwrite that file's content while manipulating metadata fields such as `uploaded_by` to obscure the tampering.

## Impact

- **Unauthorized File Overwrite**: Attackers can replace legitimate files with malicious content, creating significant risk of malware propagation and data corruption. - **Remote Code Execution**: If the storage backend is shared with the extensions location, attackers can deploy malicious extensions that execute arbitrary code when loaded. - **Data Integrity Compromise**: Files can be tampered with or replaced without visible indication in the application interface.

## Mitigation

The `filename_disk` parameter should be treated as a server-controlled value. Uniqueness of storage paths must be enforced server-side, and `filename_disk` should be excluded from the fields users are permitted to update directly.