The BGP implementation in Cisco NX-OS does not properly filter segment types in AS paths, which allows remote attackers to cause a denial of service (BGP service reset) via a malformed UPDATE message, aka Bug ID CSCtn13043.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2012-4041
http://tools.cisco.com/security/center/content/CiscoSecurityNotice/CVE-2012-4097