Ubuntu 12.04 LTS / 14.04 LTS / 15.10 : libssh vulnerabilities (USN-2912-1)

Medium Nessus Plugin ID 88930


The remote Ubuntu host is missing a security-related patch.


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).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.


Update the affected libssh-4 package.

Plugin Details

Severity: Medium

ID: 88930

File Name: ubuntu_USN-2912-1.nasl

Version: $Revision: 2.7 $

Type: local

Agent: unix

Published: 2016/02/24

Modified: 2016/12/01

Dependencies: 12634

Risk Information

Risk Factor: Medium


Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Temporal Vector: CVSS2#E:U/RL:OF/RC:C


Base Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:libssh-4, cpe:/o:canonical:ubuntu_linux:12.04:-:lts, cpe:/o:canonical:ubuntu_linux:14.04, cpe:/o:canonical:ubuntu_linux:15.10

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2016/02/23

Reference Information

CVE: CVE-2015-3146, CVE-2016-0739

OSVDB: 134850

USN: 2912-1