Asterisk PJSIP Channel Driver DoS (AST-2014-009)
Low Nessus Plugin ID 77858
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 denial of service vulnerability in the PJSIP channel driver. This is due to a flaw in the 'res_pjsip_pubsub' module. The issue is triggered when handling a SIP SUBSCRIBE request with unexpected mixes of headers for a given event package. By using a specially crafted request, a remote attacker could exploit this to crash the application.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
SolutionUpgrade to Asterisk 12.5.1 or apply the appropriate patch listed in the Asterisk advisory.