Rule: -- Sid: 329 -- Summary: This is an intelligence gathering activity. This event is indicative of a connection laundering attack against the finger daemon -- Impact: The attacker may obtain information about a third party host without making a direct connection to that host. -- Detailed Information: The event is generated when an attempt to use a machine to run finger queries against a third party UNIX system is attempted by the Cybercop vulnerability scanner. The attack utilizes "finger forwarding" functionality, normally used to forward queries to a third party machine. The information is obtained without a direct connection to the said third party, since the target system performs a connection to the third party host for the attacker. The Finger daemon is used to provide information about users on a UNIX system. It used to be installed and enabled by default on most UNIX/Linux systems. The attack if successful, will confirm that the target host will try to forward queries. -- Attack Scenarios: An attacker uses the Cybercop vulnerability scanner to test for this weakness. -- Ease of Attack: Simple, performed by a scanner -- False Positives: None Known -- False Negatives: None Known -- Corrective Action: Disable the finger daemon or upgrade to a daemon without finger forwarding functionality -- Contributors: Original rule written by Max Vision <vision@whitehats.com> Snort documentation contributed by Anton Chuvakin <http://www.chuvakin.org> Sourcefire Research Team Nigel Houghton <nigel.houghton@sourcefire.com> -- Additional References: CVE: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-1999-0105 Arachnids: http://www.whitehats.com/info/IDS11 --
