Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code.† Updates are available.
Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code.
The vulnerability is due to errors in processing malformed Session Initiation Protocol (SIP) messages by an affected device.† An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious request to the targeted device.† Successful exploitation could allow the attacker to execute arbitrary code.
Cisco confirmed the vulnerability in a security advisory and released updated software.
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.
Depending on site configurations, an attacker may require access to internal networks to exploit the vulnerability.† Some sites restrict voice services that require SIP protocol processing to separate physical or logical networks, making exploitation more difficult.† If an exploit is successful, the attacker could execute arbitrary commands on the device, possibly allowing the attacker to gain complete control over the device.
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 execute arbitrary code on the device.
The vulnerability is due to errors in processing malformed SIP messages by an affected device.† An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious SIP packet to a device via TCP and UDP ports 5060 or TCP port 5061.† Only devices with services that are configured to accept and process SIP network traffic are vulnerable to exploitation.† The processing of a malicious packet could trigger an error condition that the attacker could use to execute arbitrary code on the device with elevated privileges.
Administrators are advised to apply the available software updates.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators may consider disabling SIP listening ports on devices that are not required to process voice network traffic.
Administrators are advised to implement an intrusion prevention system (IPS) or intrusion detection system (IDS) to help detect and prevent attacks that attempt to exploit this vulnerability.
Administrators are advised to monitor critical systems.
The Cisco Applied Intelligence team has created the following companion document to guide administrators in identifying and mitigating attempts to exploit this vulnerability prior to applying updated software: cisco-amb-20100324-voice
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 firstname.lastname@example.org.
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.