Debusine is an integrated solution to build, distribute and maintain a Debian-based distribution. Debian source packages (.dsc) and upload artifacts (.changes) are manifest files that name the files that make up the artifact. The parser used to read these files in Debusine accepted arbitrary fully user-controlled paths. The mergeuploads task could be abused to create arbitrary symbolic links on a worker, overwriting any file that the worker user has access to.
Weakness
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Debusine | Ubuntu | upstream | * |
Potential Mitigations
- Follow the principle of least privilege when assigning access rights to entities in a software system.
- Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/132.html
- https://cwe.mitre.org/data/definitions/17.html
- https://cwe.mitre.org/data/definitions/35.html
- https://cwe.mitre.org/data/definitions/76.html