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Re: Fortigate Bypass

hi there
   https is born to make connection keep secret between two peers.
Only the two end of a connection can see the clear text, gateways and
router can not see clear text. so technically, Fortigate or other
gateways can not deal with https content text. And more, if FortiGate
can know your https connect content, FortiGate administartor can see
your credit card account and password when you logon bank website
throught FortiGate by https, would you like to see this thing? :)


19 Jul 2006 06:14:12 -0000, digicrimes@xxxxxxxxx <digicrimes@xxxxxxxxx>:
Today when I was trying to see how strong the fortiguard filters where I had stepped upon some thing interesting .

Note : fortiguard clearly says that none of their filters work on HTTPS ;) so you guys need to decide if its worth the money u shell in hehe

Scenario 1

Say you have blocked Web based email in your fortiguard policy and you check it by going to http://www.gamil.com . you see that you could have access to the login page of gamil in spite   of blocking it. So you try to log in and see its it blocks and once you log in it block perfectly saying it�s a Webbased email site.  And you url would read " Http://mail.google.com/mail/?auth=DQAAAG0AAADkxf81BT4k5Q_dw7zQsGO2RuHEQ55IOMzbimKF8Ia7WbQZHvXuVo7o5smHQGg9C_nC4SQz2ofiC3hhc8q4Ar14V-PqgtawN>>>>>>> � in your browser. But if a user prefix the same url with a https instead of Http he can get into his Gmail account. The firewall is unable to even log this activity ( memory logging).

Scenario 2

Let�s take an example of Proxy avoidance ( I know it�s a nightmare for admin�s) . say a user tries to access http://www.kproxy.com  . Fortiguard beautifully blocks it under the Proxy avoidance category. But if the user prefix a https then he can get into the site and from there he is virtually un stoppable form accessing any shit he wants ( no logs again).

Solution 1

You need to input a policy that Block all the Https protocols. Well if you do this all the ligament sites such as ( MSDN just an example ) or say your Im�s  would get blocked. If you want to exclude suck secure sites you need to go and find all the ip�s they would use ( that�s not really easy)  and then allow then Https access.

Solution 2

Find all the sites that allow Https Proxy and block them. Just a reminder that each of the would have tone of ips and most of them keep changing frequently.

Solution 3

Fortiguard makes the filters work with https :D

Tried on

Fortinet OS 3 Mr1

Fortinet OS 3 Mr2







Have a Good Day