GLSA-201601-01 : OpenSSH: Multiple vulnerabilities

high Nessus Plugin ID 87985
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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: High

ID: 87985

File Name: gentoo_GLSA-201601-01.nasl

Version: 2.6

Type: local

Published: 1/19/2016

Updated: 1/11/2021

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 4.6

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

CVSS v3

Risk Factor: High

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: 1/16/2016

Reference Information

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

GLSA: 201601-01