Cisco IOS and IOS XE Software Session Initiation Protocol Denial of Service Vulnerability
A vulnerability in the common Session Initiation Protocol (SIP) library of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient sanity checks on an internal data structure. An attacker could exploit this vulnerability by sending a sequence of malicious SIP messages to an affected device. An exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the iosd process. This triggers a reload of the device.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.