Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
The vulnerability exists due to an unspecified error in the handling of transiting Session Initiation Protocol (SIP) packets on systems that are configured with Cisco IOS Zone-Based Policy Firewall SIP Inspection enabled. An unauthenticated, remote attacker could exploit this vulnerability by sending a crafted SIP packet through the affected firewall. When the affected device inspects the packet, the device may reload, resulting in a DoS condition.
Cisco has confirmed this vulnerability and released software updates.
Cisco has published a list of affected Cisco IOS Software releases in the security advisory. The Vendor Announcements section of this alert contains a link to the advisory.
Cisco IOS Firewall Context-Based Access Control (CBAC) support for SIP inspection using the ip inspect name sip is not susceptible to this vulnerability.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
An unauthenticated, remote attacker could exploit this vulnerability to cause the affected device to reload, resulting in a DoS condition.
Additional technical information is not available.
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling Cisco IOS Zone-Based Policy Firewall SIP inspection as a mitigation to this vulnerability.
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 e-mail at email@example.com.
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.