Snort mailing list archives
Re: Re: [Snort-sigs] Re: Fw: Cisco Vulnerability Testing Results
From: Rich Adamson <radamson () routers com>
Date: Sun, 20 Jul 2003 11:41:27 -0600
Right on! I was going to post a similar response (only without the ttl observation), but your response covers it nicely. For the purposes of an ethernet-based snort, I'd have to guess and say the ttl is likely to be any value and should not be included in the rule. ------------------------
alert ip $EXTERNAL_NET any -> $HOME_NET any (msg: "CISCO: IP Proto 53 (Swipe) detected"; ip_proto: 53; classtype:denial-of-service;) alert ip $EXTERNAL_NET any -> $HOME_NET any (msg: "CISCO: IP Proto 55 (IP Mobility) detected"; ip_proto: 55; classtype:denial-of-service;) alert ip $EXTERNAL_NET any -> $HOME_NET any (msg: "CISCO: IP Proto 77 (SUN ND) detected"; ip_proto: 77; classtype:denial-of-service;) alert ip $EXTERNAL_NET any -> $HOME_NET any (msg: "CISCO: IP Proto 103 (PIM) detected"; ip_proto: 103; classtype:denial-of-service;)A couple of thoughts: 1) as discussed on a couple of other lists, the ttl at the destination device would be 0? or 1? (guess I need to attack myself and look) 2) I would expect that our snort boxes are NOT configured on the WAN (serial/frame relay/fiber) side of our routers so we won't pick up directed attacks against our correct router, however, any dual WAN routers that are used for our subnets will pick it up, as well as anyone doing address sweeps. Without snort listening on the OUTSIDE of your router, you won't pick up the attack. 3) The CISCO released ACL snipps may prove a better way to watch the traffic (put the acl's on for the above protocols, even if you have upgraded your firmware and use the 'log' or 'log-interface' option if you have multiple interfaces. If you want to feed these logs to snort, you can do it with one of several add-ons, or, make snort sig to watch the syslog udp going from your router to your syslog server.
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Current thread:
- Re: Fw: Cisco Vulnerability Testing Results Jon Hart (Jul 18)
- Re: [Snort-sigs] Re: Fw: Cisco Vulnerability Testing Results William Stearns (Jul 18)
- Re: [Snort-sigs] Re: Fw: Cisco Vulnerability Testing Results Michael Scheidell (Jul 20)
- Re: Re: [Snort-sigs] Re: Fw: Cisco Vulnerability Testing Results Rich Adamson (Jul 20)
- snort.conf Tantravahi Venkata Aditya (Jul 20)
- RE: snort.conf Scott Renna (Jul 20)
- preprocessor logs Tantravahi Venkata Aditya (Jul 20)
- Re: preprocessor logs Matt Kettler (Jul 21)
- Viewing ACID set's off P..O..R..N rules ... Jason Whitson (Jul 21)
- RE: Viewing ACID set's off P..O..R..N rules ... Scott Renna (Jul 21)
- Re: Viewing ACID set's off P..O..R..N rules ... Jason Whitson (Jul 21)
- RE: Viewing ACID set's off P..O..R..N rules ... Scott Renna (Jul 21)
- Re: Re: [Snort-sigs] Re: Fw: Cisco Vulnerability Testing Results Rich Adamson (Jul 20)
- <Possible follow-ups>
- Re: Fw: Cisco Vulnerability Testing Results Marc Quibell (Jul 22)