A vulnerability in the implementation of the Network Time Protocol (NTP) feature in Cisco IOS Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.
The vulnerability is due to the improper handling of multicast NTP packets that are sent to an affected device encapsulated in a Multicast Source Discovery Protocol (MSDP) Source-Active (SA) message from a configured MSDP peer.
An attacker could exploit this vulnerability by sending multicast NTP packets to an affected device. Repeated exploitation could result in a sustained DoS condition.
Cisco has released free software updates that address this vulnerability.
A workaround is available to mitigate this vulnerability.
This advisory is available at the following link: http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130925-ntp
Note: The September 25, 2013, Cisco IOS Software Security Advisory bundled publication includes eight Cisco Security Advisories.
All advisories address vulnerabilities in Cisco IOS Software. Each Cisco IOS Software Security Advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all Cisco IOS Software vulnerabilities in the September 2013 bundled publication.
Individual publication links are in “Cisco Event Response: Semiannual Cisco IOS Software Security Advisory Bundled Publication” at the following link: