CVE-2021-43845: Debian Linux

Critical severity, CVSS 9.1. EPSS: 3.6% chance of exploitation in the next 30 days.

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 Debian Linux: version 9.0 only; version 10.0 only; version 11.0 only
• Teluu Pjsip: up to and including 2.11.1

Published 2021-12-27. Last modified 2026-06-17.