Synopsis

Moderate: libssh security update

Type/Severity

Security Advisory: Moderate

Topic

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.

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.

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.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64

Fixes

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

CVEs

• CVE-2016-0739

References