By design, the "established" command on the Cisco PIX firewall allows connections from one host to arbitrary ports of a target host if an alternative conduit has already been allowed, which can cause administrators to configure less restrictive access controls than intended if they do not understand this functionality.
- http://www.cisco.com/warp/public/707/pixest-pub.shtml
- http://www.kb.cert.org/vuls/id/6733
No PoCs found on GitHub currently.