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CVE Request: GnuTLS: GNUTLS-SA-2015-2: MD5-based ServerKeyExchange signature accepted by default
From: Salvatore Bonaccorso <carnil () debian org>
Date: Tue, 5 May 2015 10:47:49 +0200
Hi I wonder if the following issue in GnuTLS should get a CVE: http://www.gnutls.org/security.html#GNUTLS-SA-2015-2
Karthikeyan Bhargavan reported that a ServerKeyExchange signature sent by the server is not verified to be in the acceptable by the client set of algorithms. That has the effect of allowing MD5 signatures (which are disabled by default) in the ServerKeyExchange message. It is not believed that this bug can be exploited because a fraudulent signature has to be generated in real-time which is not known to be possible. However, since attacks can only get better it is recommended to update to a GnuTLS version which addresses the issue.
Details: https://lists.gnupg.org/pipermail/gnutls-devel/2015-April/007572.html https://bugzilla.redhat.com/show_bug.cgi?id=1218426 https://lists.gnupg.org/pipermail/gnutls-devel/2015-May/007577.html https://lists.gnupg.org/pipermail/gnutls-devel/2015-May/007578.html Upstream commit: https://gitlab.com/gnutls/gnutls/commit/7d9d5c61f8445dc9e9ca47bb575c77cef17da17a Testcase: https://gitlab.com/gnutls/gnutls/commit/6822a37947d4e38c45b1afc0121cda35ba897182 Regards, Salvatore
Current thread:
- CVE Request: GnuTLS: GNUTLS-SA-2015-2: MD5-based ServerKeyExchange signature accepted by default Salvatore Bonaccorso (May 05)