4.3 - RHSA-2016:0566

Problem Description:

An update for libssh is now available for Red Hat Enterprise Linux 7 Extras.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux 7 Extras - x86_64

3. Description:

libssh is a library which implements the SSH protocol. It can be used to implement client and server applications.

Security Fix(es):

* A type confusion issue was found in the way libssh generated ephemeral secrets for the diffie-hellman-group1 and diffie-hellman-group14 key exchange methods. This would cause an SSHv2 Diffie-Hellman handshake to use significantly less secure random parameters. (CVE-2016-0739)

Red Hat would like to thank Aris Adamantiadis for reporting this issue.

4. Solution:

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing these updated packages, all running applications using libssh must be restarted for this update to take effect.

5. Bugs fixed (https://bugzilla.redhat.com/):

1305971 - CVE-2016-0739 libssh: bits/bytes confusion resulting in truncated Difffie-Hellman secret length