Description
Use-after-free vulnerability in Sendmail before 8.13.8 allows remote attackers to cause a denial of service (crash) via a long "header line", which causes a previously freed variable to be referenced. NOTE: the original developer has disputed the severity of this issue, saying "The only denial of service that is possible here is to fill up the disk with core dumps if the OS actually generates different core dumps (which is unlikely)... the bug is in the shutdown code (finis()) which leads directly to exit(3), i.e., the process would terminate anyway, no mail delivery or receiption is affected."
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 | 8.13.8-1 | — |
| Debian 13 | sendmail | 8.13.8-1 | — |
| Debian 12 | sendmail | 8.13.8-1 | — |
| Debian 3.1 | sendmail | 8.13.4-3sarge3 | DSA-1164 |
Advisories 1
- DSA-1164 sendmail - programming error Debian Security (DSA / DLA) · Mar 9, 2026
References
- [3.9] 20060825 005: SECURITY FIX: August 25, 2006 vendor-advisory
- 20060829 Sendmail vendor dispute - CVE-2006-4434 (fwd) mailing-list
- 1016753 vdb-entry
- 21637 third-party-advisory
- ADV-2006-3994 vdb-entry
- 28193 vdb-entry
- 21749 third-party-advisory
- 21700 third-party-advisory
- DSA-1164 vendor-advisory
- 21641 third-party-advisory
- http://www.sendmail.org/releases/8.13.8.html
- ADV-2006-3393 vdb-entry
- MDKSA-2006:156 vendor-advisory
- 19714 vdb-entry
- SUSE-SR:2006:021 vendor-advisory
- 102664 vendor-advisory
- 22369 third-party-advisory
- [3.8] 20060825 010: SECURITY FIX: August 25, 2006 vendor-advisory
- 21696 third-party-advisory