Vulnerability Alert

Cisco IOS Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

The vulnerability is due to errors in processing malformed Skinny Client Control Protocol (SCCP) network messages.  An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious request to the targeted device.  Successful exploitation could allow the attacker to cause the device to reload, resulting in a DoS condition.

Cisco has 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.

To exploit this vulnerability, an attacker must be able to send a malicious request originating from a registered IP address to a targeted device.  If autoregistration is enabled, which is the default configuration, an attacker could register an IP address and use that address to send a malicious request.  The attacker may require access to internal networks to send a request to a device.

If an exploit is successful, the attacker could cause a targeted device to stop responding and automatically reload, resulting in a DoS condition.  The device would be unable to process network requests while it starts.  Repeated attacks could cause the device to continue to reload, resulting in an extended DoS condition as long as the requests continue.

Cisco has released a security advisory for Cisco bug ID CSCsz48614 at the following link: cisco-sa-20100324-cucme