Novell Groupwise arbitrary file retrieval vulnerability

[Stuart McClure <stuart.mcclure () foundstone com>]

FS Advisory ID:         FS-101501-20-GWSE

Release Date:           October 15, 2001

Product:                Novell GroupWise

Vendor:                 Novell (http://www.novell.com)

Vendor Advisory:        See vendor website.

Type:                   Arbitrary file retrieval vulnerability

Severity:               High

Author:                 Mike Shema (mike.shema () foundstone com)
                        Foundstone, Inc. (http://www.foundstone.com)

Operating Systems:      Windows 2000

Vulnerable versions:    GroupWise 5.5, 6

Foundstone Advisory:
http://www.foundstone.com/cgi-bin/display.cgi?Content_ID=327
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Description

        A vulnerability exists with Novell's GroupWise server which
        allows for the arbitrary viewing of files anywhere on the
        system. This includes files outside of the web root, but on
        the same volume as the web server.

Details

        The Novell GroupWise server has a web-based front-end for
        users to access e-mail and other functions of the server. The
        default login page is accessed by the URL:

        /servlet/webacc

        The webacc usually accesses templates from the "/" directory;
        however, the servlet will follow directory path traversal. 
        It is possible to view the full path of the server install by
        passing an invalid argument to the User.html variable:
        
        /servlet/webacc?User.html=noexist

        which will display the full path of the GroupWise install.

        Arbitrary files can be read by the webacc servlet by passing
        the appropriate file name and appending a null character to
        the string:

        /servlet/webacc?User.html=../../../../../../../../boot.ini%00

        Administrators should note that the Groupwise configuration
        files can be viewed with this exploit. Care should be taken 
        to limit the amount of sensitive data within these files.
        
Proof of concept

        From a browser, make the following URL request:

        http://server:port/servlet/webacc?User.html=../../../../../../
        ../../boot.ini%00

Solution

        Please contact the vendor for a solution. Customers should
        obtain upgraded software by contacting their customer support
        representative to obtain patches.

        The severity of this vulnerability and vulnerabilities of a 
        similar nature can be significantly reduced by installing the
        GroupWise server (or other application) files on a disk volume
        separate from the windows system root.

Credits

        We would also like to thank Novell for their reaction
        to this problem and their co-operation in heightening security
        awareness in the security community.

Disclaimer

        The information contained in this advisory is the copyright
        (C) 2001 of Foundstone, Inc. and believed to be accurate at
        the time of printing, but no representation or warranty is
        given, express or implied, as to its accuracy or
        completeness. Neither the author nor the publisher accepts
        any liability whatsoever for any direct, indirect or
        conquential loss or damage arising in any way from any use
        of, or reliance placed on, this information for any purpose.
        This advisory may be redistributed provided that no fee is
        assigned and that the advisory is not modified in any way.