Asterisk ReceiveFax Dialplan Application Remote DoS (AST-2014-010)
Low Nessus Plugin ID 77859
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 ReceiveFax Dialplan application. This is due to a flaw in the 'res_fax_spandsp' module, which is caused by the improper handling of out-of-call messages. 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 11.12.1 / 12.5.1 / 11.6-cert6 or apply the appropriate patch listed in the Asterisk advisory.