An OpenSSH security update to address an integer overflow has been released for Gentoo Linux

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Gentoo Linux Security Advisory GLSA 201911-01 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - https://security.gentoo.org/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Severity: Normal
Title: OpenSSH: Integer overflow
Date: November 07, 2019
Bugs: #697046
ID: 201911-01

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Synopsis
========

An integer overflow in OpenSSH might allow an attacker to execute arbitrary code.

Background
==========

OpenSSH is a complete SSH protocol implementation that includes SFTP client and server support.

Affected packages
=================

------------------------------------------------------------------- Package / Vulnerable / Unaffected ------------------------------------------------------------------- 1 net-misc/openssh >= 8.0_p1-r2 >= 8.0_p1-r4
Description
===========

OpenSSH, when built with "xmss" USE flag enabled, has a
pre-authentication integer overflow if a client or server is configured to use a crafted XMSS key.

NOTE: This USE flag is disabled by default!

Impact
======

A remote attacker could connect to a vulnerable OpenSSH server using a special crafted XMSS key possibly resulting in execution of arbitrary code with the privileges of the process or a Denial of Service condition.

Workaround
==========

Disable XMSS key type.

Resolution
==========

All OpenSSH users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot -v ">=net-misc/openssh/openssh-8.0_p1-r4"
References
==========

[ 1 ] CVE-2019-16905
https://nvd.nist.gov/vuln/detail/CVE-2019-16905

Availability
============

This GLSA and any updates to it are available for viewing at the Gentoo Security Website:

https://security.gentoo.org/glsa/201911-01

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users' machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.

License
=======

Copyright 2019 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5