mail2sms.sh in smsclient 2.0.8z allows local users to overwrite arbitrary files via a symlink attack on a (1) /tmp/header.##### or (2) /tmp/body.##### temporary file, or append data to arbitrary files via a symlink attack on the (3) /tmp/sms.log temporary file.
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 |
|---|---|---|---|
| Smsclient | Smsclient | 2.0.8z (including) | 2.0.8z (including) |
| Smsclient | Ubuntu | dapper | * |
| Smsclient | Ubuntu | gutsy | * |
| Smsclient | Ubuntu | hardy | * |
| Smsclient | Ubuntu | intrepid | * |
| Smsclient | Ubuntu | jaunty | * |
| Smsclient | Ubuntu | karmic | * |
| Smsclient | Ubuntu | lucid | * |
| Smsclient | Ubuntu | maverick | * |
| Smsclient | Ubuntu | natty | * |
| Smsclient | Ubuntu | oneiric | * |
| Smsclient | Ubuntu | precise | * |
| Smsclient | Ubuntu | quantal | * |
| Smsclient | Ubuntu | raring | * |
| Smsclient | Ubuntu | saucy | * |
| Smsclient | Ubuntu | trusty | * |
| Smsclient | Ubuntu | utopic | * |
| Smsclient | Ubuntu | vivid | * |
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