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 PJSIP before version 2.11.1 there are a couple of issues found in the SSL socket. First a race condition between callback and destroy due to the accepted socket having no group lock. Second the SSL socket parent/listener may get destroyed during handshake. Both issues were reported to happen intermittently in heavy load TLS connections. They cause a crash resulting in a denial of service. These are fixed in version 2.11.1.