Description
Directory traversal vulnerability in the setuid root helper binary in S-nail (later S-mailx) before 14.8.16 allows local users to write to arbitrary files and consequently gain root privileges via a .. (dot dot) in the randstr argument.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | s-nail | 14.8.16-1 | — |
| Debian 13 | s-nail | 14.8.16-1 | — |
| Debian 12 | s-nail | 14.8.16-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | s-nail | 14.8.6-1ubuntu0.1~esm1 | USN-4820-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- S-nail < 14.8.16 - Local Privilege Escalation EDB-47172 · local · Jan 13, 2019
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- USN-4820-1 s-nail vulnerability Ubuntu Security Notices (USN) · Jun 25, 2026
References
- [oss-security] 20170207 Re: CVE Request: s-nail local root mailing-list
- [s-nail-users] 20170127 [ANN]ounce of S-nail v14.8.16 ("Copris lunaris") mailing-list
- [oss-security] 20170127 CVE Request: s-nail local root mailing-list
- 96138 vdb-entry