Cisco IOS 12.1(3) and 12.1(3)T allows remote attackers to read and modify device configuration data via the cable-docsis read-write community string used by the Data Over Cable Service Interface Specification (DOCSIS) standard.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6180
http://www.kb.cert.org/vuls/id/840665
http://www.cisco.com/warp/public/707/ios-snmp-community-vulns-pub.shtml