os-prober in os-prober 1.17 allows local users to overwrite arbitrary files via a symlink attack on the (1) /tmp/mounted-map or (2) /tmp/raided-map temporary file. NOTE: the vendor disputes this issue, stating the insecure code path should only ever run inside a d-i environment, which has no non-root users.
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 |
|---|---|---|---|
| Os-prober | Debian | 1.17 (including) | 1.17 (including) |
| Os-prober | Ubuntu | dapper | * |
| Os-prober | Ubuntu | devel | * |
| Os-prober | Ubuntu | gutsy | * |
| Os-prober | Ubuntu | hardy | * |
| Os-prober | Ubuntu | intrepid | * |
| Os-prober | Ubuntu | jaunty | * |
| Os-prober | Ubuntu | karmic | * |
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