What’s Vulnerable › Vulnerabilities
CVE-2021-32686: Denial of Service in PJSIP
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.1% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-07-23 · updated 2026-06-17
- Weakness: CWE-362
Description
PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP before version 2.11.1, there are a couple of issues found in the SSL socket. First, a race condition between callback and destroy, due to the accepted socket having no group lock. Second, the SSL socket parent/listener may get destroyed during handshake. Both issues were reported to happen intermittently in heavy load TLS connections. They cause a crash, resulting in a denial of service. These are fixed in version 2.11.1.
Affected products
- Debian Linux: 9.0, 11.0
- teluu pjsip: before 2.11.1 — fixed in 2.11.1
How to fix
Upgrade to a fixed version: teluu pjsip 2.11.1. Check the vendor advisory for mitigations.
References
- https://github.com/pjsip/pjproject/commit/d5f95aa066f878b0aef6a64e60b61e8626e664cd
- https://github.com/pjsip/pjproject/pull/2716
- https://github.com/pjsip/pjproject/releases/tag/2.11.1
- https://github.com/pjsip/pjproject/security/advisories/GHSA-cv8x-p47p-99wr
- https://lists.debian.org/debian-lts-announce/2022/03/msg00035.html
- https://security.gentoo.org/glsa/202210-37
- https://www.debian.org/security/2021/dsa-4999
- https://github.com/pjsip/pjproject/commit/d5f95aa066f878b0aef6a64e60b61e8626e664cd
- https://github.com/pjsip/pjproject/pull/2716
- https://github.com/pjsip/pjproject/releases/tag/2.11.1
- https://github.com/pjsip/pjproject/security/advisories/GHSA-cv8x-p47p-99wr
- https://lists.debian.org/debian-lts-announce/2022/03/msg00035.html
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