GLSA-201601-01 : OpenSSH: Multiple vulnerabilities

Medium Nessus Plugin ID 87985

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VPR Score: 6.7

Synopsis

The remote Gentoo host is missing one or more security-related patches.

Description

The remote host is affected by the vulnerability described in GLSA-201601-01 (OpenSSH: Multiple vulnerabilities)

Qualys have reported two issues in the “roaming” code included in the OpenSSH client, which provides undocumented, experimental support for resuming SSH connections. An OpenSSH client could be tricked into leaking parts of its memory to a malicious server. Furthermore, a buffer overflow can be exploited by a malicious server, but its exploitation requires non-default options and is mitigated due to another bug.
Impact :

A remote attacker could entice a user to connect to a specially crafted OpenSSH server, possibly resulting in the disclosure of the user’s private keys. Users with private keys that are not protected by a passphrase are advised to generate new keys if they have connected to an SSH server they don’t fully trust.
Note that no special configuration is required to be vulnerable as the roaming feature is enabled by default on the client.
Workaround :

The issues can be worked around by disabling the roaming code. To do so, add “UseRoaming no” to the SSH client configuration, or specify “-o ‘UseRoaming no’” on the command line.

Solution

All OpenSSH users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose '>=net-misc/openssh-7.1_p2'

See Also

https://security.gentoo.org/glsa/201601-01

Plugin Details

Severity: Medium

ID: 87985

File Name: gentoo_GLSA-201601-01.nasl

Version: Revision: 2.5

Type: local

Published: 2016/01/19

Updated: 2016/10/10

Dependencies: 12634

Risk Information

Risk Factor: Medium

VPR Score: 6.7

CVSS v2.0

Base Score: 4.6

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

CVSS v3.0

Base Score: 8.1

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

Vulnerability Information

CPE: p-cpe:/a:gentoo:linux:openssh, cpe:/o:gentoo:linux

Required KB Items: Host/local_checks_enabled, Host/Gentoo/release, Host/Gentoo/qpkg-list

Patch Publication Date: 2016/01/16

Reference Information

CVE: CVE-2016-0777, CVE-2016-0778

GLSA: 201601-01