Editing Application firewall (section)

== History ==
[[Gene Spafford]] of [[Purdue University]], [[Bill Cheswick]] at [[AT&T Laboratories]], and [[Marcus Ranum]] described a third-generation firewall known as an application layer firewall. Marcus Ranum's work, based on the firewall created by [[Paul Vixie]], [[Brian Reid (computer scientist)|Brian Reid]], and Jeff Mogul, spearheaded the creation of the first commercial product. The product was released by DEC, named the DEC SEAL by [[Geoff Mulligan]] - Secure External Access Link. DEC's first major sale was on June 13, 1991, to Dupont.

Under a broader DARPA contract at TIS, Marcus Ranum, Wei Xu, and Peter Churchyard developed the Firewall Toolkit (FWTK) and made it freely available under license in October 1993.<ref>{{cite web |url=http://www.avolio.com/papers/FWTKv1.0Announcement.html |title=Firewall toolkit V1.0 release |access-date=2018-12-28}}</ref> The purposes for releasing the freely available, not for commercial use, FWTK were: to demonstrate, via the software, documentation, and methods used, how a company with (at the time) 11 years experience in formal security methods, and individuals with firewall experience, developed firewall software; to create a common base of very good firewall software for others to build on (so people did not have to continue to "roll their own" from scratch); to "raise the bar" of firewall software being used. However, FWTK was a basic application proxy requiring the user interactions.

In 1994, Wei Xu extended the FWTK with the Kernel enhancement of IP stateful filter and socket transparent. This was the first transparent firewall, known as the inception of [[Firewall (computing)#Application layer|the third generation firewall]], beyond a traditional application proxy ([[Firewall (computing)#Connection tracking|the second generation firewall]]), released as the commercial product known as Gauntlet firewall. Gauntlet firewall was rated one of the top application firewalls from 1995 until 1998, the year it was acquired by Network Associates Inc, (NAI). Network Associates continued to claim that Gauntlet was the "worlds most secure firewall" but in May 2000, security researcher [[Jim Stickley]] discovered a large vulnerability in the firewall, allowing remote access to the operating system and bypassing the security controls.<ref>{{cite web|title=Security Hole found in NAI Firewall|url=https://www.securityfocus.com/news/40|author=Kevin Pulsen|date=May 22, 2000|access-date=2018-08-14|publisher=securityfocus.com}}</ref> [[Jim Stickley|Stickley]] discovered a second vulnerability a year later, effectively ending Gauntlet firewalls' security dominance.<ref>{{cite web|title=Gaping hole in NAI's Gauntlet firewall|url=https://www.theregister.co.uk/2001/09/05/gaping_hole_in_nais_gauntlet/|author=Kevin Pulsen|date=September 5, 2001|access-date=2018-08-14|publisher=theregister.co.uk}}</ref>