GLSA 200412-01: rssh, scponly
Posted on: 12/03/2004 02:59 PM

A rssh security update has been released for Gentoo Linux

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Gentoo Linux Security Advisory GLSA 200412-01
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http://security.gentoo.org/
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Severity: Normal
Title: rssh, scponly: Unrestricted command execution
Date: December 03, 2004
Bugs: #72815, #72816
ID: 200412-01

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Synopsis
=======

rssh and scponly do not filter command-line options that can be exploited to execute any command, thereby allowing a remote user to completely bypass the restricted shell.

Background
=========

rssh and scponly are two restricted shells, allowing only a few predefined commands. They are often used as a complement to OpenSSH to provide access to remote users without providing any remote execution privileges.

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

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Package / Vulnerable / Unaffected
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1 net-misc/scponly < 4.0 >= 4.0
2 app-shells/rssh <= 2.2.2 Vulnerable!
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NOTE: Certain packages are still vulnerable. Users should migrate to another package if one is available or wait for the existing packages to be marked stable by their architecture maintainers.

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2 affected packages on all of their supported architectures.
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Description
==========

Jason Wies discovered that when receiving an authorized command from an authorized user, rssh and scponly do not filter command-line options that can be used to execute any command on the target host.

Impact
=====

Using a malicious command, it is possible for a remote authenticated user to execute any command (or upload and execute any file) on the target machine with user rights, effectively bypassing any restriction of scponly or rssh.

Workaround
=========

There is no known workaround at this time.

Resolution
=========

All scponly users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/scponly-4.0"

Currently, there is no released version of rssh that contains a fix for these issues. The author declared that he cannot provide a fixed version at this time. Therefore, the rssh package has been hard-masked prior to complete removal from Portage, and current users are advised to unmerge the package.

References
=========

[ 1 ] BugTraq Posting

http://www.securityfocus.com/archive/1/383046/2004-11-30/2004-12-06/0

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

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

http://security.gentoo.org/glsa/glsa-200412-01.xml

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 http://bugs.gentoo.org.

License
======

Copyright 2004 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/2.0


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