[gentoo-announce] [ GLSA 201601-01 ] OpenSSH: Multiple vulnerabilities

[news 28]

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Gentoo Linux Security Advisory GLSA 201601-01

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https://security.gentoo.org/

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Severity: Normal

Title: OpenSSH: Multiple vulnerabilities

Date: January 16, 2016

Bugs: #571892

ID: 201601-01

 

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Synopsis

========

 

Multiple vulnerabilities have been found in OpenSSH, allowing attackers

to leak client memory to a server, including private keys.

 

Background

==========

 

OpenSSH is a complete SSH protocol implementation that includes SFTP

client and server support.

 

Affected packages

=================

 

-------------------------------------------------------------------

Package / Vulnerable / Unaffected

-------------------------------------------------------------------

1 net-misc/openssh < 7.1_p2 >= 7.1_p2

 

Description

===========

 

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.

 

Resolution

==========

 

All OpenSSH users should upgrade to the latest version:

 

# emerge --sync

# emerge --ask --oneshot --verbose ">=net-misc/openssh-7.1_p2"

 

References

==========

 

[ 1 ] CVE-2016-0777

http://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0777

[ 2 ] CVE-2016-0778

http://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0778

 

Availability

============

 

This GLSA and any updates to it are available for viewing at

the Gentoo Security Website:

 

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

 

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 ( -at -) gentoo.org or alternatively, you may file a bug at

https://bugs.gentoo.org.

 

License

=======

 

Copyright 2016 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.

 

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