oss-sec mailing list archives
Re: CVE-2015-4000 - TLS does not properly convey server's ciphersuite choice
From: Florian Weimer <fweimer () redhat com>
Date: Tue, 26 May 2015 15:03:39 +0200
On 05/20/2015 08:29 PM, cve-assign () mitre org wrote:
CVE-2015-4000 has been assigned to this vulnerability in the TLS protocol that was disclosed in section 3.2 of the https://weakdh.org/imperfect-forward-secrecy.pdf paper: "a flaw in the way TLS composes DHE and DHE_EXPORT. When a server selects DHE_EXPORT for a handshake, it proceeds by issuing a signed ServerKeyExchange message containing a 512-bit p512, but the structure of this message is identical to the message sent during standard DHE ciphersuites. Critically, the signed portion of the server's message fails to include any indication of the specific ciphersuite that the server has chosen." (This is the TLS protocol problem associated with the Logjam attack.)
Would you please clarify if the CVE assignment also covers the vulnerability (and attack scenario) discussed in this earlier paper? A Cross-Protocol Attack on the TLS Protocol Nikos Mavrogiannopoulos, Frederik Vercauteren, Vesselin Velichkov, Bart Preneel, “A Cross-Protocol Attack on the TLS Protocol” (2012) <http://homes.esat.kuleuven.be/~fvercaut/papers/ACM2012.pdf> Thanks. -- Florian Weimer / Red Hat Product Security
Current thread:
- CVE-2015-4000 - TLS does not properly convey server's ciphersuite choice cve-assign (May 20)
- Re: CVE-2015-4000 - TLS does not properly convey server's ciphersuite choice Yves-Alexis Perez (May 20)
- Re: CVE-2015-4000 - TLS does not properly convey server's ciphersuite choice Florian Weimer (May 26)