CVE & CISA-KEV Catalog

CVE-2021-32686

MEDIUMEPSS 79th pctl
5.9
CVSS v3
NVD

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.

How to fix

Remediation Available
asteriskDebian
Fixed in:1:16.16.1~dfsg-1+deb11u1CVE-2021-32686
Fixed in:1:16.16.1~dfsg-2CVE-2021-32686
libpj2Ubuntu
Fixed in:2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1USN-8122-1
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1
libpjmedia2Ubuntu
Fixed in:2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1USN-8122-1
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1
libpjnath2Ubuntu
Fixed in:2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1USN-8122-1
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1
libpjsip2Ubuntu
Fixed in:2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1USN-8122-1
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1
libpjsua2Ubuntu
Fixed in:2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1USN-8122-1
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1
pjprojectUbuntu
Fixed in:2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1USN-8122-1
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1
python-pjprojectUbuntu
Fixed in:2.7.2~dfsg-1ubuntu0.1~esm1USN-8122-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

2.08%probability of exploitation in 30 days
79thpercentile

Elevated risk: more likely to be exploited than 79% of all known CVEs.

References

Related Vulnerabilities

Other CWE-362 (Race Condition) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2024-6387High8.1100%-Fix
CVE-2023-36884High7.599%KEV + RansomFix
CVE-2018-15473Medium5.399%-Fix
CVE-2024-27983High8.287%-Fix
CVE-2014-0226Medium6.886%-Fix
CVE-2016-5195High7.084%KEVFix
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Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-04.