CVE-2021-43804

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.