CVE-2021-26906
Publication date 18 February 2021
Last updated 25 August 2025
Ubuntu priority
Description
An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| asterisk | ||
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
|
| 14.04 LTS trusty | Not in release |
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
5.9 · Medium
|
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
References
Other references
- http://packetstormsecurity.com/files/161477/Asterisk-Project-Security-Advisory-AST-2021-005.html
- http://seclists.org/fulldisclosure/2021/Feb/61
- https://downloads.asterisk.org/pub/security/
- https://downloads.asterisk.org/pub/security/AST-2021-005.html
- https://issues.asterisk.org/jira/browse/ASTERISK-29196
- https://www.cve.org/CVERecord?id=CVE-2021-26906