KBTAG: kben10000060
URL:
http://www.securityportal.com/lskb/10000050/kben10000060.html
Date created: 17/07/2000
Date modified:
Date removed:
Authors(s): Kurt Seifried seifried@securityportal.com
Topic: Firewall scanners
Keywords: Network/Firewall
There are also a number of programs now that scan firewalls and execute other penetration tests in order to find out how a firewall is configured.
Firewalk is a program that uses a traceroute style of packets to scan a firewall and attempt to deduce the rules in place on that firewall. By sending out packets with various time to lives and seeing where they die or are refused a firewall can be tricked into revealing rules. There is no real defense against this apart from silently denying packets instead of sending a rejection message which hopefully will reveal less. I would advise utilizing this tool against your systems as the results can help you tighten up security. Firewalk is available from: http://www.packetfactory.net/firewalk/.