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Gentoo Linux Security Advisory                           GLSA 201801-05
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                                           https://security.gentoo.org/
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 Severity: Normal
    Title: OpenSSH: Permission issue
     Date: January 07, 2018
     Bugs: #633428
       ID: 201801-05

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Synopsis
========

A flaw has been discovered in OpenSSH which could allow a remote
attacker to create zero-length files.

Background
==========

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

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

    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  net-misc/openssh           < 7.5_p1-r3              >= 7.5_p1-r3 

Description
===========

The process_open function in sftp-server.c in OpenSSH did not properly
prevent write operations in readonly mode.

Impact
======

A remote attacker could cause the creation of zero-length files.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All OpenSSH users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=net-misc/openssh-7.5_p1-r3"

References
==========

[ 1 ] CVE-2017-15906
      https://nvd.nist.gov/nvd.cfm?cvename=CVE-2017-15906

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

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

 https://security.gentoo.org/glsa/201801-05

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
=======