Subject: NetBSD Security Advisory YYYY-NNN
To: None <netbsd-announce@netbsd.org>
From: None <security-officer@netbsd.org>
List: current-users
Date: 10/26/2000 19:32:44
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                 NetBSD Security Advisory 2000-014
                 =================================

Topic:		Global-3.55 allows world-wide executable cgi.
Version:	any before 4.01
Severity:	permits remote execution of arbitrary shell commands


Abstract
========

When using the CGI interface of the Global v3.55 package, it's 
possible to execute random commands. 


Technical Details
=================

The exploit of this is possible due to insufficient handling of quoted
or escaped characters in this version, and command line arguments that
are then handed off to shell commands. 


Solutions and Workarounds
=========================

To find out if you have the problematic version of the global package
installed, type

	pkg_info -e global

If this displays "global-3.55" or below, you are vulnerable.  If
this displays "global-4.0.1" or higher, your system is not vulnerable
either. If this displays no output at all, it means you don't have
the "global" package installed, and your system is not vulnerable.

If your system is vulnerable, the best solution is to upgrade to the latest
version in pkgsrc, which is 4.0.1 as of this writing. 

There are precompiled binary packages of global for some NetBSD ports
available from:

ftp://ftp.netbsd.org/pub/NetBSD/packages/pkgsrc/devel/global/README.html

If no precompiled binary is available for your platform, you can build
your own from source.  First, make sure that you have a version of the
pkgsrc hierarchy from October 9th 2000 or later.  (See
http://www.netbsd.org/Sites/net.html for ways to obtain NetBSD, and
pkgsrc, its packages collection.)

You can then install the new version of the package:

        cd pkgsrc/devel/global; make clean; make install

For more information on how to rebuild a package from source for your
architecture, see ftp://ftp.netbsd.org/pub/NetBSD/packages/pkgsrc/README

To render the vulnerability unexploitable, modify the file
'HTML/cgi-bin/global.cgi' around line 35, and change the generated HTML
from:

$pattern =~ s/'//g;                     # to shut security hole

to

$pattern =~ s/"//g;                     # to shut security hole


Thanks To
=========

The problem was reported in NetBSD PR 11165 by the author of global, 
Shigio Yamaguchi <shigio@tamacom.com>. The package updated by as a
collaboration of Hubert Feyrer <hubertf@netbsd.org> and David Brownlee
<abs@netbsd.org>. Hubert Feyrer also drafted this security advisory.


Revision History
================

20001009 First draft, after the pkg was committed by abs.


More Information
================

Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.ORG/ and http://www.NetBSD.ORG/Security/.


Copyright 2000, The NetBSD Foundation, Inc.  All Rights Reserved.

$NetBSD: NetBSD-SA2000-014.txt,v 1.4 2000/10/24 14:50:55 agc Exp $


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