HOWTO: Create a rogue CA certificate for $2000

An international group of researchers—speaking at the 25th Chaos Communication Club conference—published details on how they had managed to construct a rogue Certificate Authority (CA) certificate (!) using a weakness in the MD5 hashing algorithm. They estimate the attack costs $20,000 to execute today, but that the cost can be reduced to as little as $2000. With a rogue CA certificate in hand they are able to impersonate any SSL-enabled web site and conduct MITM attacks undetected (no browser warnings!).

The presentation is now available for download.

Update (30 Dec): And so is the paper, along with more information and a demonstration site (the CA  certificate was purposefully constructed to expire in 2004, which essentially makes it harmless).

Update (31 Dec): Verisign fixes the problem.

Comments

[Jim Manico]

Ivan - will forcing clients to TLS 1.0 make a difference here at all?

[Ivan Ristić]

No, forcing TLS v1.0 or any later version won't help. The fault lies with the CA who not only continued to use MD5 long past its due date, but also had a system in place that allowed the researchers to predict the serial number--which was required to carry out the attack. Now that Verisign fixed the problem (see the link above) the future attacks of this type will fail. I don't think there's any need for you as an individual to be concerned with this attack vector, but the community will need to work harder to make attacks similar to this one more difficult in the future. The CAs will need to put better standards in place, and the browser vendors will need to start closely monitoring the CAs activities to ensure compliance.

[Aa'ed Alqarta]

Imagine malware authors and phishers start combining rogue ca certificates and infect users's systems and redirect them to a "fake bank website with valid certificate" ... boom !

read more ...

http://extremesecurity.blogspot.com/2008/12/kaminskys-dns-bug-rogue-ca-certificates.html