Backdoor

An undocumented way of gaining access to computer system. A backdoor is a potential security risk.

See CNSSI 4009-2015 (NIST SP 800-82 Rev. 1) and NIST SP 800-12 Rev. 1 under Back door (NIST SP 800-82 Rev. 2) for more information.

A malicious program that listens for commands on a certain Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) port.

See NIST SP 800-83 Rev. 1 under Backdoor for more information.