Description
Sendmail 8.9.0 through 8.12.3 allows local users to cause a denial of service by obtaining an exclusive lock on the (1) alias, (2) map, (3) statistics, and (4) pid files.
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 | sendmail | 8.12-4 | — |
| Debian 13 | sendmail | 8.12-4 | — |
| Debian 12 | sendmail | 8.12-4 | — |
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 2
- Sendmail 8.9.x/8.10.x/8.11.x/8.12.x - File Locking Denial of Service (1) EDB-21476 · dos · May 24, 2002 · verified
- Sendmail 8.9.x/8.10.x/8.11.x/8.12.x - File Locking Denial of Service (2) EDB-21477 · dos · May 24, 2002 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- 20020524 Sendmail file locking - PoC mailing-list
- sendmail-file-locking-dos(9162) vdb-entry
- 4822 vdb-entry
- http://www.sendmail.org/LockingAdvisory.txt