Asterisk Endpoint Provisional Response Parsing RTP Port Consumption Remote DoS (AST-2012-010)
Medium Nessus Plugin ID 60064
SynopsisA telephony application running on the remote host is affected by a denial of service vulnerability.
DescriptionAccording to the version in its SIP banner, the version of Asterisk running on the remote host is potentially affected by a vulnerability that could allow a remote, authenticated attacker to exhaust the server of resources.
If an endpoint sends a provisional response to the server's re-INVITE message, certain data structures are not freed. More iterations of this sequence lead to exhaustion of all available RTP ports.
SolutionUpgrade to Asterisk Open Source 18.104.22.168 / 10.5.2, Business Edition C.3.7.5, Certified Asterisk 1.8.11-cert4 or apply the patches listed in the Asterisk advisory.