An issue has been discovered in GitLab CE/EE affecting all versions from 13.2 before 18.0.6, 18.1 before 18.1.4, and 18.2 before 18.2.2 that could have allowed authenticated users to create a denial of service condition by sending specially crafted markdown payloads to the Wiki feature.
Weakness
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Gitlab | Gitlab | 13.2.0 (including) | 18.0.6 (excluding) |
| Gitlab | Gitlab | 18.1.0 (including) | 18.1.4 (excluding) |
| Gitlab | Gitlab | 18.2.0 (including) | 18.2.2 (excluding) |
| Gitlab | Ubuntu | esm-apps/xenial | * |
Extended Description
Attackers can create crafted inputs that
intentionally cause the regular expression to use
excessive backtracking in a way that causes the CPU
consumption to spike.