Description
Asterisk Open Source 1.8 before 1.8.32.3, 11.x before 11.17.1, 12.x before 12.8.2, and 13.x before 13.3.2 and Certified Asterisk 1.8.28 before 1.8.28-cert5, 11.6 before 11.6-cert11, and 13.1 before 13.1-cert2, when registering a SIP TLS device, does not properly handle a null byte in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority.
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 | asterisk | 1:13.7.2~dfsg-1 | — |
| Debian 8 | asterisk | 1:11.13.1~dfsg-2+deb8u1 | DSA-3700-1 |
| Debian 7 | asterisk | 1:1.8.13.1~dfsg1-3+deb7u4 | DLA-455-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | asterisk | No fix yet | — |
Advisories 2
- DLA-455-1 asterisk - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3700-1 asterisk - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://packetstormsecurity.com/files/131364/Asterisk-Project-Security-Advisory-AST-2015-003.html
- 74022 vdb-entry
- MDVSA-2015:206 vendor-advisory
- http://advisories.mageia.org/MGASA-2015-0153.html
- 1032052 vdb-entry
- http://downloads.asterisk.org/pub/security/AST-2015-003.html
- 20150408 AST-2015-003: TLS Certificate Common name NULL byte exploit mailing-list
- 20150408 AST-2015-003: TLS Certificate Common name NULL byte exploit mailing-list
- DSA-3700 vendor-advisory
- FEDORA-2015-5948 vendor-advisory