Description
The SIP channel driver (chan_sip) in Asterisk before 1.2.18 and 1.4.x before 1.4.3 does not properly parse SIP UDP packets that do not contain a valid response code, which allows remote attackers to cause a denial of service (crash).
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 | 1:1.4.2~dfsg-1 | — |
| Debian 4.0 | asterisk | 1:1.2.13~dfsg-2etch1 | DSA-1358-1 |
| Debian 3.1 | asterisk | 1:1.0.7.dfsg.1-2sarge5 | DSA-1358-1 |
Advisories 1
- DSA-1358-1 asterisk Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://www.asterisk.org/files/ASA-2007-011.pdf
- http://bugs.digium.com/view.php?id=9313
- SUSE-SA:2007:034 vendor-advisory
- 1017954 vdb-entry
- 24359 vdb-entry
- 20070425 ASA-2007-011: Multiple problems in SIP channel parser handling response codes mailing-list
- 25582 third-party-advisory
- asterisk-sip-response-dos(33892) vdb-entry
- 2644 third-party-advisory
- DSA-1358 vendor-advisory