oss-sec mailing list archives

Re: Re: Possible CVE request: subversion MD5 collision authentication leak


From: Ben Reser <ben () reser org>
Date: Mon, 04 Aug 2014 23:56:40 -0700

On 8/4/14 6:38 PM, Michael Samuel wrote:
Just to clarify - does the attacker have control of both $REALM parameters?

Only their own server.  If they had access to the server they were attacking
they would presumably have access to the repository directly and could do
anything they wanted already.

A chosen prefix collision still requires the attacker provide both
inputs (or at-least the suffix to both inputs).

I stand corrected.  Re-read the documentation at the link I shared earlier and
you're right you need to be able to modify the suffix on both sides of the
collision.

Which means that yes this is theoretical.

Thanks for setting me right.


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