Re: Evading Client-Certificate Authentication

From: Brad Showalter (pris_brad@yahoo.com)
Date: Thu Apr 22 2004 - 13:40:19 EDT


('binary' encoding is not supported, stored as-is) In-Reply-To: <BAY10-DAV30G10Gai4o0001d88c@hotmail.com>

This is late, my last response never made it to the list, but you may find it useful in future engagements.

Instead of attempting to fool the server, look for vulnerable clients likely to already be in possession of valid web certs (more easily accomplished in internal pen studies than external ones). I believe, by default, the IE browser does not require a password to protect the cert store, so there is a good chance you'd be able to simply export the browser cert to your PC once having gained access to the vulnerable client. Netscape/Mozilla requires password protection of cert stores, to the best of my knowledge, but are very prevalent in corporate environments.

Best of luck,
-Brad

>Hi to all,
>
>whilst in the middle of a Penetration Test I stumbled on a web server only
>serving SSL and demanding the client to present
>a certificate to identify himself.
>I tried to nikto it with sslproxy and browse the site thru paros both with a
>temporary Verisign personal certificate.
>No such luck, the server keeps bouncing me off. Even vulnerability scanners
>like Nessus and Retina don't get passed
>the port-scan portion.
>
>Does anyone have an idea to further assess this server? Am I looking at a
>mission impossible here maybe?
>
>Thanks,
>
>~kevin

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