Summary
TREK contains an object-level authorization flaw in collaborative trip note-file deletion. An authenticated user with edit access to one trip may provide identifiers from another trip and permanently delete its note attachment when the target is resolved without validating trip ownership.
Affected context
The issue occurs in the collaborative trip API's note-file deletion flow when authorization checks rely on a client-supplied trip identifier, but the service resolves the note and file using only their identifiers. Deployments are exposed when identifiers can be obtained or guessed and the deletion service does not confirm that the target note and file belong to the authorized trip.
Exploit preconditions
- Attack surface: Authenticated collaborative trip API
- Required access: Edit access to at least one trip
- Trigger point: Deletion of a note-file attachment through the collaboration endpoint
- Target condition: The supplied note and file identifiers belong to another trip
- Why exploitation is possible: The request-level trip authorization is not enforced again when the service resolves the note and file objects
Why this happens
The underlying bug is an object-level authorization mismatch. The endpoint authorizes the caller against an attacker-controlled trip identifier, while the deletion service locates the target using only note and file identifiers. This insecure pattern maps primarily to CWE-639: Authorization Bypass Through User-Controlled Key, with CWE-862: Missing Authorization also applying because ownership and relationship checks are absent at the operation's final target.
Potential impact
- An attacker may permanently delete attachments from other users' trip notes.
- Collaborative trip content could be damaged or lost.
- Repeated or sequential targeting could enable broad integrity-impacting abuse.
- Users may lose access to operational, personal, or planning information stored in attachments.
General mitigation guidance
Mitigation generally focuses on enforcing authorization at the point where the target object is loaded and modified.
Common defensive patterns include:
- Resolve the trip, note, and file through a single authorized relationship rather than independent identifiers.
- Verify that every object belongs to the requested trip and that the caller has the required permission.
- Treat route parameters and object identifiers as untrusted input, even after authentication.
- Use deny-by-default authorization policies with centralized relationship checks.
- Apply least privilege to collaboration roles and require explicit permission for destructive actions.
- Use transactional deletion and audit logging to improve accountability and recovery.
How teams detect issues like this
Detection approaches can include:
- Static analysis and code review checks for database lookups that use object IDs without parent-resource constraints.
- Reviewing authorization middleware and service methods to confirm that permission checks occur on the final object being changed.
- Testing mismatched parent, child, note, and file identifiers across users and trips.
- Adding policy tests for cross-tenant and cross-trip destructive operations.
- Monitoring deletion events for unusual rates, sequential identifier patterns, or repeated authorization failures.
- Using automated security review tools to flag direct object references lacking relationship-based authorization.
