Description
sendmail before 8.14.4 does not properly handle a '\0' character in a Common Name (CN) field of an X.509 certificate, which (1) allows man-in-the-middle attackers to spoof arbitrary SSL-based SMTP servers via a crafted server certificate issued by a legitimate Certification Authority, and (2) allows remote attackers to bypass intended access restrictions via a crafted client certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.
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 | 8.14.3-9.1 | — |
| Debian 13 | sendmail | 8.14.3-9.1 | — |
| Debian 12 | sendmail | 8.14.3-9.1 | — |
| Debian 5.0 | sendmail | 8.14.3-5+lenny1 | DSA-1985-1 |
| Debian 4.0 | sendmail | 8.13.8-3+etch1 | DSA-1985-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | sendmail +3 | 8.13.8-8.el5 | RHSA-2010:0237 |
| RHEL 4 | sendmail +3 | 8.13.1-6.el4 | RHSA-2011:0262 |
Advisories 3
- RHSA-2010:0237 Red Hat Security Advisory: sendmail security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2011:0262 Red Hat Security Advisory: sendmail security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1985-1 sendmail - insufficient input validation Debian Security (DSA / DLA) · Mar 9, 2026
References
- 38314 third-party-advisory
- GLSA-201206-30 vendor-advisory
- 1021797 vendor-advisory
- 39088 third-party-advisory
- ADV-2009-3661 vdb-entry
- 37998 third-party-advisory
- 37543 vdb-entry
- ADV-2011-0415 vdb-entry
- 43366 third-party-advisory
- SUSE-SR:2010:006 vendor-advisory
- oval:org.mitre.oval:def:10255 vdb-entry signature
- http://www.sendmail.org/releases/8.14.4
- HPSBUX02508 vendor-advisory
- ADV-2010-0719 vdb-entry
- RHSA-2011:0262 vendor-advisory
- DSA-1985 vendor-advisory
- oval:org.mitre.oval:def:11822 vdb-entry signature
- 40109 third-party-advisory
- 38915 third-party-advisory
- ADV-2010-1386 vdb-entry