Cyber Resilience

CVE-2021-32686

Medium

Published: 23 July 2021

Published
23 July 2021
Modified
04 November 2025
KEV Added
Patch
CVSS Score v3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0168 82.6th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-32686 is a medium-severity Race Condition (CWE-362) vulnerability in Debian Debian Linux. Its CVSS base score is 5.9 (Medium).

Operationally, ranked in the top 17.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

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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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

teluu
pjsip
≤ 2.11.1
debian
debian linux
11.0, 9.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-362

Accurate timestamps from internal clocks enable detection of race conditions by providing reliable event ordering in audit logs.

addresses: CWE-362

Coordination of concurrent security activities reduces the probability that shared resources will be accessed simultaneously without proper synchronization.

References