Firewall Wizards mailing list archives
Re: PIX -> ISA -> OWA Configuration
From: Jason Gomes <greyline () phreaker net>
Date: Tue, 03 May 2005 21:53:13 -1000
It sounds like you would completely and solely trust ISA to protect OWA and your entire internal network.
In #2 if either the ISA or OWA server is compromised, wouldn't the back-end firewall limit the potential damage that could be done to the Internal Network? ACLs would dictate which of those AD ports would be allowed open and to specific, hardened, back-end servers.
In #1, a single exploit against OWA (ignoring any protection ISA may provide which would be available in both scenarios) would allow an attacker free reign to target anything internally without restriction.
Paul Melson wrote:
Definitely. In #1, if the ISA server is configured via the OWA publishing wizard, it will create ACL's that prevent requests that don't match /exchange/* from being passed to IIS. You can also run urlscan at the ISA server (though it requires some tweaking to keep from breaking some of OWA's functionality). In #2, the same thing applies, but should the ISA server be compromised say via buffer overflow, then there is no protection for the internal AD domain, since those holes must be punched straight through the firewall (and they are BIG holes). PaulM -----Original Message----- Subject: Re: [fw-wiz] PIX -> ISA -> OWA Configuration Definitely? Under #1 it seems like something as simple as a directory traversal attack against IIS/OWA that manages to get through ISA leaves your entire internal network exposed. Under #2 it appears to me that an attacker would need at the very least a second exploit to gain further access to the trusted network.-----Original Message-----What is the preferred placement for a OWA front-end server given these two possible network configurations and why?1) [Internet] <==> [PIX Firewall] <==> [ISA Proxy] <==> [PIX Firewall] <==> [OWA] <==> [Internal Net w/Exchange Svr]2) [Internet] <==> [PIX Firewall] <==> [ISA Proxy] <==> [OWA] <==> [PIX Firewall] <==> [Internal Net w/Exchange Svr]
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Current thread:
- RE: PIX -> ISA -> OWA Configuration, (continued)
- RE: PIX -> ISA -> OWA Configuration Paul Melson (May 02)
- Re: PIX -> ISA -> OWA Configuration Danny (May 05)
- Re: PIX -> ISA -> OWA Configuration Jason Gomes (May 03)
- RE: PIX -> ISA -> OWA Configuration Paul Melson (May 03)
- Re: PIX -> ISA -> OWA Configuration Kevin (May 05)
- Re: PIX -> ISA -> OWA Configuration Jason Gomes (May 05)
- RE: PIX -> ISA -> OWA Configuration Frank Knobbe (May 05)
- RE: PIX -> ISA -> OWA Configuration Paul Melson (May 03)
- RE: PIX -> ISA -> OWA Configuration Thomas W Shinder (May 05)
- FW: PIX -> ISA -> OWA Configuration Paul Melson (May 05)
- RE: PIX -> ISA -> OWA Configuration Sanford Reed (May 05)
- Re: PIX -> ISA -> OWA Configuration Jason Gomes (May 05)
- PIX -> ISA -> OWA Configuration woodsd001 (May 05)
- RE: PIX -> ISA -> OWA Configuration Paul Melson (May 05)
- Re: PIX -> ISA -> OWA Configuration Michael Brown (May 08)
- RE: PIX -> ISA -> OWA Configuration Mark Tinberg (May 08)
- Re: PIX -> ISA -> OWA Configuration Victor Williams (May 08)
- Re: PIX -> ISA -> OWA Configuration Chris Blask (May 12)
- RE: PIX -> ISA -> OWA Configuration Paul Melson (May 05)
- Message not available
- RE: PIX -> ISA -> OWA Configuration Chris Blask (May 17)