Ubuntu 12.04 LTS / 14.04 LTS / 15.04 : openssh regression (USN-2710-2)

High Nessus Plugin ID 85533

Synopsis

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

Description

USN-2710-1 fixed vulnerabilities in OpenSSH. The upstream fix for CVE-2015-5600 caused a regression resulting in random authentication failures in non-default configurations. This update fixes the problem.

Moritz Jodeit discovered that OpenSSH incorrectly handled usernames when using PAM authentication. If an additional vulnerability were discovered in the OpenSSH unprivileged child process, this issue could allow a remote attacker to perform user impersonation. (CVE number pending)

Moritz Jodeit discovered that OpenSSH incorrectly handled context memory when using PAM authentication. If an additional vulnerability were discovered in the OpenSSH unprivileged child process, this issue could allow a remote attacker to bypass authentication or possibly execute arbitrary code. (CVE number pending)

Jann Horn discovered that OpenSSH incorrectly handled time windows for X connections. A remote attacker could use this issue to bypass certain access restrictions. (CVE-2015-5352)

It was discovered that OpenSSH incorrectly handled keyboard-interactive authentication. In a non-default configuration, a remote attacker could possibly use this issue to perform a brute-force password attack.
(CVE-2015-5600).

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.

Solution

Update the affected openssh-server package.

See Also

https://usn.ubuntu.com/2710-2/

Plugin Details

Severity: High

ID: 85533

File Name: ubuntu_USN-2710-2.nasl

Version: 2.5

Type: local

Agent: unix

Published: 2015/08/19

Updated: 2020/09/22

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 8.5

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

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:openssh-server, cpe:/o:canonical:ubuntu_linux:12.04:-:lts, cpe:/o:canonical:ubuntu_linux:14.04, cpe:/o:canonical:ubuntu_linux:15.04

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

Patch Publication Date: 2015/08/18

Vulnerability Publication Date: 2015/08/02

Reference Information

CVE: CVE-2015-5352, CVE-2015-5600

USN: 2710-2