The init script in kbd, possibly 1.14.1 and earlier, allows local users to overwrite arbitrary files via a symlink attack on /dev/shm/defkeymap.map.
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 |
|---|---|---|---|
| Kbd | Kbd-project | * | 1.14.1 (including) |
| Kbd | Kbd-project | 0.99 (including) | 0.99 (including) |
| Kbd | Kbd-project | 1.01 (including) | 1.01 (including) |
| Kbd | Kbd-project | 1.03 (including) | 1.03 (including) |
| Kbd | Kbd-project | 1.04 (including) | 1.04 (including) |
| Kbd | Kbd-project | 1.05 (including) | 1.05 (including) |
| Kbd | Kbd-project | 1.06 (including) | 1.06 (including) |
| Kbd | Kbd-project | 1.08 (including) | 1.08 (including) |
| Kbd | Kbd-project | 1.10 (including) | 1.10 (including) |
| Kbd | Kbd-project | 1.11 (including) | 1.11 (including) |
| Kbd | Kbd-project | 1.12 (including) | 1.12 (including) |
| Kbd | Kbd-project | 1.13 (including) | 1.13 (including) |
| Kbd | Kbd-project | 1.14 (including) | 1.14 (including) |
| Opensuse | Opensuse | 11.2 (including) | 11.2 (including) |
| Opensuse | Opensuse | 11.3 (including) | 11.3 (including) |
| Kbd | Ubuntu | hardy | * |
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