Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in session initiation protocol functionality of Cisco IOS Software could allow an unauthenticated, remote attacker to trigger a memory leak or a device reload.
The vulnerability is due to incorrect processing of specially crafted SIP messages. An attacker could exploit this vulnerability by sending specific valid SIP messages to the SIP gateway. An exploit could allow the attacker to trigger a memory leak or a device reload.
Cisco has confirmed the vulnerability in a security advisory and released software updates.
Cisco IOS Software Releases 15.1(4)GC, 15.1(4)GC1, 15.1(4)M4, 15.1(4)M5, and 15.1(4)M6 are affected.
Only specific releases of Cisco IOS Software configured to perform SIP message processing are affected. This configuration requirement greatly reduces the number of vulnerable systems.
An unauthenticated, remote attacker could exploit this vulnerability to cause a vulnerable device to reload, resulting in a DoS condition.
The vulnerability is due to improper processing of Session Initiation Protocol (SIP) messages by Cisco IOS Software.
An unauthenticated, remote attacker could exploit the vulnerability by sending malicious SIP messages to the targeted system. The processing of the malicious messages could cause the device to consume available memory resources or reload, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor affected systems.
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at firstname.lastname@example.org.
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