An issue has been discovered in GitLab CE/EE affecting all versions starting with version 8.10. It was possible to trigger a timeout on a page with markdown by using a specific amount of block-quotes.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Gitlab | Gitlab | 8.10 (including) | 14.5.4 (including) |
| Gitlab | Gitlab | 14.6 (including) | 14.6.4 (including) |
| Gitlab | Gitlab | 14.7 (including) | 14.7.1 (including) |
| Gitlab | Ubuntu | esm-apps/xenial | * |
| Gitlab | Ubuntu | trusty | * |
| Gitlab | Ubuntu | xenial | * |
Potential Mitigations
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html