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

What is CVE-2021-43845?

CVE-2021-43845 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 27 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-125

Which versions are affected by CVE-2021-43845?

It affects 2 products.

Products include Debian Debian Linux, Teluu Pjsip.

How do I fix CVE-2021-43845?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-43845 being exploited?

There is no known exploitation of CVE-2021-43845 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2021-43845, DEBIAN-CVE-2021-43845, GHSA-r374-qrwv-86hh, UBUNTU-CVE-2021-43845.