Description
tmux 1.3 and 1.4 does not properly drop group privileges, which allows local users to gain utmp group privileges via a filename to the -S command-line option.
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 | tmux | 1.4-6 | — |
| Debian 13 | tmux | 1.4-6 | — |
| Debian 12 | tmux | 1.4-6 | — |
| Debian 6.0 | tmux | 1.3-2+squeeze1 | DSA-2212-1 |
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
- tmux 1.3/1.4 - '-S' Option Incorrect SetGID Privilege Escalation EDB-17147 · local · Apr 11, 2011
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-2212-1 tmux - privilege escalation Debian Security (DSA / DLA) · Mar 9, 2026
References
- ADV-2011-1015 vdb-entry
- 44081 third-party-advisory
- 44239 third-party-advisory
- 17147 exploit
- FEDORA-2011-5156 vendor-advisory
- 47283 vdb-entry
- DSA-2212 vendor-advisory
- ADV-2011-0897 vdb-entry
- ADV-2011-1002 vdb-entry
- FEDORA-2011-5486 vendor-advisory
- FEDORA-2011-5167 vendor-advisory
- tmux-setgid-privilege-escalation(66693) vdb-entry