Penetration Testing mailing list archives
RE: PIX and ttl
From: "Fernando Cardoso" <fernando.cardoso () whatevernet com>
Date: Fri, 25 May 2001 19:21:47 +0100
I'm doing a pen-test for a client that has a "standard" config of router-firewall-server_in_dmz. I'm fingerprinting the setup andI'm awarethat the firewall is a Cisco PIX (BTW is there any way tochange the bannerfor the fixup protocol smtp? :)no way, but i think that security configuration of the MTA behind the pix it's thw right way and that "fixup protocol smtp" isn't necessary. It simply add overhead to the Firewall processing...
Fully agreed.
Their router is at 5 hops of distance from me. Both router andfw gives methe ttl I was expecting when I ping them (251 and 250), but allthe serversin the DMZ don't... traceroute to server_in_dmz (x.x.x.x), 30 hops max, 38 byte packets 1 a.a.a.a (a.a.a.a) 2.068 ms 2.031 ms 2.349 msTTL:2552 a.a.a.a (a.a.a.a) 153.681 ms 152.925 ms 131.445 msTTL:2543 a.a.a.a (a.a.a.a) 205.197 ms 269.539 ms 145.973 msTTL:2534 a.a.a.a (a.a.a.a) 38.078 ms 23.849 ms 23.497 msTTL:2525 router (router) 31.445 ms 27.277 ms 28.422 msTTL:2516 * * * (fw)TTL:2507 * * * (server_in_dmz)TTL:123The servers in the DMZ are Microsoft boxes so the "right" TTLshould be 122. No, it's different from release to release of microsoft products...
I don't think so... I've tested all kind of Windows stuff and I always get 128 (local LAN). Maybe the results you're showing are the result of some kind of "PIX tweaking".
-- Windows NT 4.0 x86 SP6a ( ttl = 128 ) in MY LAN 46 bytes from 10.1.3.20: flags=SA seq=0 ttl=128 id=25884 win=8576 rtt=0.5 ms
OK
-- Windows 2k x86 SP1 ( ttl = 123 ) behind PIX 5.3(1) 46 bytes from xxx.xxx.xx.xxx: flags=SA seq=0 ttl=123 id=10872 win=8576 rtt=27.3 ms -- Windows NT 4.0 x86 unknown SP ( ttl = 118 ) behind 5.3(1) 46 bytes from xxx.xxx.xxx.xxx: flags=SA seq=0 ttl=118 id=45018 win=32768 rtt=860.1 ms
Are these two on the same network? If my guesses are correct the first one would be at 7 hops from your box (like in my example) and the second one at 12 hops.
-- PIX Itself 5.3(1) ( ttl = 247 ) 64 octets from xxx.xxx.xxx.x: icmp_seq=0 ttl=247 time=87.7 ms -- PIX Itself 5.1(4) ( ttl = 251 ) 64 octets from xxx.xxx.xxx.xx: icmp_seq=0 ttl=251 time=102.4 ms
Same hop distance these two?? That would be odd.
As you could see ttl it's different for the same pix release... I HATE PIX, I HATE CISCO ;>
Time for a Checkpoint FW-1 :) -- Fernando Cardoso - Security Consultant WhatEverNet Computing, S.A. Phone : +351 21 7994200 Praca de Alvalade, 6 - Piso 6 Fax : +351 21 7994242 1700-036 Lisboa - Portugal email : fernando.cardoso () whatevernet com http://www.whatevernet.com/ _____________________________________________________________________ INTERNET MAIL FOOTER A presente mensagem pode conter informação considerada confidencial. Se o receptor desta mensagem não for o destinatário indicado, fica expressamente proibido de copiar ou endereçar a mensagem a terceiros. Em tal situação, o receptor deverá destruir a presente mensagem e por gentileza informar o emissor de tal facto. --------------------------------------------------------------------- Privileged or confidential information may be contained in this message. If you are not the addressee indicated in this message, you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. ---------------------------------------------------------------------
Current thread:
- PIX and ttl Fernando Cardoso (May 24)
- RE: PIX and ttl Jason Lewis (May 25)
- RE: PIX and ttl Fernando Cardoso (May 25)
- Re: PIX and ttl Konstantin Rozinov (May 27)
- RE: PIX and ttl Jacek Lipkowski (May 25)
- RE: PIX and ttl Jason Lewis (May 26)
- RE: PIX and ttl Fernando Cardoso (May 25)
- <Possible follow-ups>
- Re: PIX and ttl Fabio Pietrosanti (naif) (May 25)
- RE: PIX and ttl Fernando Cardoso (May 25)
- Re: PIX and ttl Nelson Brito (May 26)
- RE: PIX and ttl Fernando Cardoso (May 25)
- Re: RE: PIX and ttl Fernando Cardoso (May 28)
- RE: RE: PIX and ttl Filipe Almeida (May 28)
- RE: RE: PIX and ttl Dario Ciccarone (May 28)
- RE: RE: PIX and ttl Filipe Almeida (May 28)
- Re: RE: RE: PIX and ttl Fernando Cardoso (May 28)
- Re: RE: RE: PIX and ttl Eugene Tsyrklevich (May 29)
- Re: RE: RE: PIX and ttl Fernando Cardoso (May 28)
- RE: PIX and ttl Jason Lewis (May 25)