IntelliShield has updated this alert to add affected products related to the Cisco IOS and IOS XE Software IP Service Level Agreement denial of service vulnerability.
A vulnerability exists in the implementation of the IP Service Level Agreement responder feature of Cisco IOS Software that could allow an unauthenticated, remote attacker to cause a reload of the vulnerable device.
The vulnerability is due to improper validation of IP SLA packets on UDP port 1167. An attacker could exploit this vulnerability by sending malformed IP SLA packets addressed to the affected device. An exploit could allow the attacker to cause an extended DoS condition.
Cisco confirmed the vulnerability in a security advisory and released updated software.
Cisco devices running an affected version of Cisco IOS and IOS XE Software and have a vulnerable IP SLA general responder configuration are affected.
Cisco has published a list of affected Cisco IOS and IOS XE Software releases in the security advisory. The Vendor Announcements section of this alert contains a link to the advisory.
It is likely that an attacker would need to have access to an internal, private network to send crafted IP SLA packets to a targeted device. This access requirement decreases the likelihood of a successful exploit.
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 a targeted device to reload. Repeated exploitation could result in a sustained DoS condition.
The vulnerability is due to improper validation of IP SLA packets on UDP port 1167 by the IP Service Level Agreement responder feature used by the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by sending specially crafted IP SLA packets to the affected port. If the attack is successful, the attacker could cause an affected device to reload, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
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 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 firstname.lastname@example.org.
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