Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Wed, 21 Mar 2012 12:32:59 +0100
From: Stefan Cornelius <>
Subject: CVE request: GnuTLS TLS record handling issue / MU-201202-01


Correcting myself as more details about the GnuTLS case were revealed:
GnuTLS needs a CVE after all, for another issue different from

Quoting the Mu Dynamics advisory [1]:

The block cipher decryption logic in GnuTLS assumed that a record
containing any data which was a multiple of the block size was valid for
further decryption processing, leading to a heap corruption vulnerability.

The bug can be reproduced in GnuTLS 3.0.14 by creating a corrupt
GenericBlockCipher struct with a valid IV, while everything else is
stripped off the end, while the handshake message length retains its
original value: [...]

This will cause a segmentation fault, when the ciphertext_to_compressed
function tries to give decrypted data to _gnutls_auth_cipher_add_auth
for HMAC verification, even though the data length is invalid, and it
should have returned GNUTLS_E_DECRYPTION_FAILED or
_gnutls_auth_cipher_add_auth was called.

NOTE: This CVE request is only for the GnuTLS TLS record handling issue
/ MU-201202-01. When looking at the release notes [2] and [3], there are
other issues that may be worthy of a CVE, but are currently still under

** libgnutls: Eliminate double free during SRP
authentication. Reported by Peter Penzov.

** libgnutls: PKCS #11 objects that do not have ID
no longer crash listing. Reported by Sven Geggus.

-- References --

[1] Mu Dynamics:

[2] GnuTLS 3.0.15 release announcement:

[3] GnuTLS 2.12.17 release announcement:

[4] GNUTLS-SA-2012-2:

[5] Red Hat bug:

Thanks and kind regards,
Stefan Cornelius / Red Hat Security Response Team

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.