Penetration Testing mailing list archives
Re: Evading IDS?
From: Antonio Varni <avarni () cj com>
Date: Thu, 18 Mar 2004 18:05:09 -0800 (PST)
I've always disliked the idea of an IDS that actively responds to perceived attacks. Unless it only acts on alerts that stem from established TCP connections it might be easy to knock it offline by spoofing a UDP attack from it's default gateway (or something similar). What one person views as a security measure could also be viewed as more functionality that can potentially be influenced by an attacker. I would try all the anti-IDS features of nessus/nikto, just because it's a commercial system doens't automatically make it a good IDS. Maybe you could bombard the IDS with suspect traffic using isic in hopes of temporarily disabling it while you conduct your scan? If you On Thu, 18 Mar 2004, Mark G. Spencer wrote:
I've come across what I assume is an IDS during some network reconnaissance. I am able to run nmap (connect scan, default ports) against the entire target class C in question without any problems, but when I run Nikto against any of the webservers, Nikto output dies just after the trace/track method information and I am then unable to access anything on the target class C for a set period of time - at least fifteen minutes. If I move to a different netblock, I can access the target class C again .. well, until I run Nikto. ;) It looks like all the routing and VPN gear on the target class C is Cisco based, so I'll make an assumption for now that the IDS is also Cisco. Any advice on how to evade the IDS? I know Nessus and Nikto offer a variety of IDS evasion techniques, but am I correct in assuming that a vendor such as Cisco (or any large vendor) has taken well-known evasion techniques into account? I will try different combinations of evasion techniques today and hopefully won't run out of open class C IP addresses on my network as I continue getting 15min+ blacklisted. Thanks for the advice, Mark
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Current thread:
- Evading IDS? Mark G. Spencer (Mar 18)
- RE: Evading IDS? Matt Foster (Mar 19)
- Re: Evading IDS? Al Smolkin (Mar 19)
- RE: Evading IDS? Rob Shein (Mar 19)
- RE: Evading IDS? Antonio Varni (Mar 21)
- RE: Evading IDS? Rob Shein (Mar 19)
- RE: Evading IDS? Jerry Shenk (Mar 19)
- Re: Evading IDS? Antonio Varni (Mar 19)
- <Possible follow-ups>
- RE: Evading IDS? Golomb, Gary (Mar 19)
- Re: Evading IDS? Rogan Dawes (Mar 19)
- RE: Evading IDS? Mark G. Spencer (Mar 22)
- RE: Evading IDS? Billy Dodson (Mar 19)
- RE: Evading IDS? Levinson, Karl (Mar 19)
- RE: Evading IDS? Mark G. Spencer (Mar 19)
- RE: Evading IDS? Gary E. Miller (Mar 21)
- RE: Evading IDS? Mark G. Spencer (Mar 19)
- RE: Evading IDS? Eric McCarty (Mar 19)
- RE: Evading IDS? Billy Dodson (Mar 21)