Ubuntu Security Notice USN-2912-1
23rd February, 2016
libssh vulnerabilities
A security issue affects these releases of Ubuntu and its
derivatives:
- Ubuntu 15.10
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS
Summary
Several security issues were fixed in libssh.
Software description
- libssh
– A tiny C SSH library
Details
Mariusz Ziulek discovered that libssh incorrectly handled certain packets.
A remote attacker could possibly use this issue to cause libssh to crash,
resulting in a denial of service.
(CVE-2015-3146)
Aris Adamantiadis discovered that libssh incorrectly generated ephemeral
secret keys of 128 bits instead of the recommended 1024 or 2048 bits when
using the diffie-hellman-group1 and diffie-hellman-group14 methods. If a
remote attacker were able to perform a man-in-the-middle attack, this flaw
could be exploited to view sensitive information. (CVE-2016-0739)
Update instructions
The problem can be corrected by updating your system to the following
package version:
- Ubuntu 15.10:
-
libssh-4
0.6.3-3ubuntu3.2
- Ubuntu 14.04 LTS:
-
libssh-4
0.6.1-0ubuntu3.3
- Ubuntu 12.04 LTS:
-
libssh-4
0.5.2-1ubuntu0.12.04.6
To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.