When a Gitea Actions run was inserted, older runs in the same workflow-level concurrency group were cancelled without checking whether the new run still needed approval. Because fork pull request runs are inserted under the base repository, a user who can open a pull request from a fork could cancel trusted in-progress runs that share a concurrency group with cancel-in-progress enabled, without approval and without running any code. On self-hosted runners this can interrupt deployments and leave partial state behind.
Weakness
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
Extended Description
Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/25.html
- https://cwe.mitre.org/data/definitions/26.html
- https://cwe.mitre.org/data/definitions/27.html