Description
Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, an authenticated attacker may cause a heap buffer overflow through an out-of-bounds write in the `Codec2` decoder caused by a `floor/ceil sample-count mismatch`. The `codec_codec2` module must be loaded and `Codec2` must be configured on the attacked endpoint. The attacker must pass SIP authentication by username/password or `source IP address matching`, establish a call using `Codec2`, and send carefully crafted `Codec2` audio packets. This issue is fixed in Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| asterisk | asterisk | < 20.20.1, >= 21.0.0-pre1, < 21.12.3, >= 22.0.0-pre1, < 22.10.1, >= 23.0.0-pre1, < 23.4.1 | — |
| asterisk | certified-asterisk | < 20.7-cert11, >= 22.8-cert1-pre1, < 22.8-cert3 | — |
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 | 1:22.10.1+dfsg+~cs6.17.60671434-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | asterisk | No fix yet | — |
| Ubuntu 26.04 LTS | asterisk | No fix yet | — |
| Ubuntu 24.04 LTS | asterisk | No fix yet | — |
| Ubuntu 22.04 LTS | asterisk | No fix yet | — |
| Ubuntu 20.04 LTS | asterisk | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | asterisk | No fix yet | — |
| Ubuntu Pro 16.04 LTS | asterisk | No fix yet | — |
Advisories 1
- WID-SEC-2026-2094 Digium Certified Asterisk: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 4, 2026
References
- https://github.com/asterisk/asterisk/security/advisories/GHSA-qf8j-jp7h-c5hx
- https://github.com/asterisk/asterisk/commit/02e2d8d51efe1f811f2929224339cb1a35ffc079
- https://github.com/asterisk/asterisk/commit/4f5cad0611c67638a0a61cfedbe645045da8dd56
- https://github.com/asterisk/asterisk/commit/9b085d48fb66e90a0740ea59e26840421fd07acb
- https://github.com/asterisk/asterisk/commit/a0bc717b2261f4df7cdecc22b58a5fffbd1aa398
- https://github.com/asterisk/asterisk/commit/a2f1cc611f7d0f21faa03e8535009df3041c434c
- https://github.com/asterisk/asterisk/commit/aa40bc599a8e628859ef1c4fc944261423ceac0d
- https://github.com/asterisk/asterisk/commit/d4ccfd55ffd7cf6d73a6e5cde347a7464c301006
- https://github.com/asterisk/asterisk/releases/tag/20.20.1
- https://github.com/asterisk/asterisk/releases/tag/21.12.3
- https://github.com/asterisk/asterisk/releases/tag/22.10.1
- https://github.com/asterisk/asterisk/releases/tag/23.4.1
- https://github.com/asterisk/asterisk/releases/tag/certified-20.7-cert11
- https://github.com/asterisk/asterisk/releases/tag/certified-22.8-cert3
- https://github.com/asterisk/asterisk/tree/24.0.0-pre1