snmpd in Cisco IOS XR 5.1 and earlier allows remote authenticated users to cause a denial of service (process reload) via a malformed SNMPv2 packet, aka Bug ID CSCun67791.
https://exchange.xforce.ibmcloud.com/vulnerabilities/96066
http://www.securitytracker.com/id/1030878
http://www.securityfocus.com/bid/69959
http://tools.cisco.com/security/center/viewAlert.x?alertId=35774
http://tools.cisco.com/security/center/content/CiscoSecurityNotice/CVE-2014-3377