CVE-2021-43804

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 affected versions if the incoming RTCP BYE message contains a reason's length, this declared length is not checked against the actual received packet size, potentially resulting in an out-of-bound read access. This issue affects all users that use PJMEDIA and RTCP. A malicious actor can send a RTCP BYE message with an invalid reason length. Users are advised to upgrade as soon as possible. There are no known workarounds.

How to fix CVE-2021-43804

To remediate CVE-2021-43804, upgrade the affected package to a fixed version below.

• —upgrade to 2.12-r0 or later
• —upgrade to 1:16.28.0~dfsg-0+deb11u1 or later
• —upgrade to 20210112.2.b757bac~ds1-1+deb11u1 or later

Is CVE-2021-43804 being exploited?

Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• from 0, < 2.12-r0
• from 0, < 1:16.28.0~dfsg-0+deb11u1
• from 0, < 20210112.2.b757bac~ds1-1+deb11u1

CVSS scores

References (2)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2021-43804
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-43804