PT-2021-6171 · Pjsip+3 · Pjsip+3

The-Storm · Published 2021-12-22 · Updated 2025-11-04 · CVE-2021-43804

Positive Technologies (AI Summary)

CVSS v2.0

7.5

High

Base vector

AV:N/AC:L/Au:N/C:P/I:P/A:P

Name of the Vulnerable Software and Affected Versions PJSIP versions prior to the fixed version

Description The issue is related to a buffer overflow in the PJSIP library when handling the length of RTCP BYE messages. This can be exploited by a remote attacker to execute arbitrary code. The problem occurs when the incoming RTCP BYE message contains a reason's length that is not checked against the actual received packet size, potentially resulting in an out-of-bound read access. This affects all users of PJMEDIA and RTCP. A malicious actor can send a RTCP BYE message with an invalid reason length.

Recommendations For PJSIP versions prior to the fixed version, upgrade to the latest version as soon as possible to resolve the issue. As a temporary workaround, consider restricting the handling of RTCP BYE messages with invalid reason lengths until a patch is available.

Fix

Out of bounds Read

Weakness Enumeration

CWE-125

Related Identifiers

ALT-PU-2024-15954

ALT-PU-2024-16030

BDU:2022-01087

CVE-2021-43804

DLA-2962-1

DLA-3194-1

DLA-3549-1

DLA-3887-1

DSA-5285-1

GHSA-3QX3-CG72-WRH9

USN-6422-1

Affected Products

Alt Linux

Linuxmint

Pjsip

Ubuntu

References · 48

• https://github.com/pjsip/pjproject/security/advisories/GHSA-3qx3-cg72-wrh9 · Patch
• https://github.com/pjsip/pjproject/commit/8b621f192cae14456ee0b0ade52ce6c6f258af1e · Patch
• https://ubuntu.com/security/CVE-2022-39244 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-43804 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-43299 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-37706 · Vendor Advisory
• https://osv.dev/vulnerability/DSA-5285-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-23608 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-24793 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-3194-1 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-43804 · Security Note
• https://ubuntu.com/security/CVE-2022-24764 · Vendor Advisory
• https://osv.dev/vulnerability/ALPINE-CVE-2021-43804 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-23537 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-43302 · Vendor Advisory