Description
There is a stack consumption vulnerability in the res_http_websocket.so module of Asterisk through 13.23.0, 14.7.x through 14.7.7, and 15.x through 15.6.0 and Certified Asterisk through 13.21-cert2. It allows an attacker to crash Asterisk via a specially crafted HTTP request to upgrade the connection to a websocket.
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 | 1:13.23.1~dfsg-1 | — |
| Debian 9 | asterisk | 1:13.14.1~dfsg-2+deb9u4 | DSA-4320-1 |
| Debian 8 | asterisk | 1:11.13.1~dfsg-2+deb8u6 | DLA-1523-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | asterisk | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | asterisk | No fix yet | — |
Advisories 2
- DSA-4320-1 asterisk - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1523-1 asterisk - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- 1041694 vdb-entry
- 20180920 AST-2018-009: Remote crash vulnerability in HTTP websocket upgrade mailing-list
- http://packetstormsecurity.com/files/149453/Asterisk-Project-Security-Advisory-AST-2018-009.html
- DSA-4320 vendor-advisory
- 20180920 AST-2018-009: Remote crash vulnerability in HTTP websocket upgrade mailing-list
- https://issues.asterisk.org/jira/browse/ASTERISK-28013
- [debian-lts-announce] 20180927 [SECURITY] [DLA 1523-1] asterisk security update mailing-list
- GLSA-201811-11 vendor-advisory
- 105389 vdb-entry
- http://downloads.asterisk.org/pub/security/AST-2018-009.html