CVE-2021-43845: Prevent out-of-bounds read in PJSIP

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-12-27 · updated 2026-06-17
Weakness: CWE-125

Description

PJSIP is a free and open source multimedia communication library. In version 2.11.1 and prior, if incoming RTCP XR message contain block, the data field is not checked against the received packet size, potentially resulting in an out-of-bound read access. This affects all users that use PJMEDIA and RTCP XR. A malicious actor can send a RTCP XR message with an invalid packet size.

Affected products

Debian Linux: 9.0, 10.0, 11.0
teluu pjsip: through 2.11.1

References

https://github.com/pjsip/pjproject/commit/f74c1fc22b760d2a24369aa72c74c4a9ab985859
https://github.com/pjsip/pjproject/pull/2924
https://github.com/pjsip/pjproject/security/advisories/GHSA-r374-qrwv-86hh
https://lists.debian.org/debian-lts-announce/2022/03/msg00035.html
https://lists.debian.org/debian-lts-announce/2022/11/msg00021.html
https://lists.debian.org/debian-lts-announce/2023/08/msg00038.html
https://security.gentoo.org/glsa/202210-37
https://www.debian.org/security/2022/dsa-5285
https://github.com/pjsip/pjproject/commit/f74c1fc22b760d2a24369aa72c74c4a9ab985859
https://github.com/pjsip/pjproject/pull/2924
https://github.com/pjsip/pjproject/security/advisories/GHSA-r374-qrwv-86hh
https://lists.debian.org/debian-lts-announce/2022/03/msg00035.html

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