Cisco Network Services (CNS) NetFlow Collection Engine (NFC) before 6.0 has an nfcuser account with the default password nfcuser, which allows remote attackers to modify the product configuration and, when installed on Linux, obtain login access to the host operating system.
https://exchange.xforce.ibmcloud.com/vulnerabilities/33861
http://www.vupen.com/english/advisories/2007/1545
http://www.securityfocus.com/bid/23647
http://www.kb.cert.org/vuls/id/127545
http://www.cisco.com/en/US/products/products_security_advisory09186a008082c520.shtml