IRM Security Advisory 002: Netware Web Server Source Disclosure

From: IRM Security Advisories (advisoriesat_private)
Date: Wed Dec 19 2001 - 03:44:25 PST

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    IRM Security Advisory No. 002
    
    Netware Web Server 5.1 Sample Page Source Disclosure
    
    Vulnerablity Type / Importance: Information Leakage / High
    
    Problem discovered: November 18th 2001
    Vendor contacted: November 20th 2001, November 29th 2001
    Advisory published: December 11th 2001
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    Abstract:
    ~~~~~~~~~
    
    Novell's Netware 5.1 is shipped with a Web Server that is installed by
    default and contains various sample web pages. There is a "viewcode"
    application that is run through a Netware Loadable Module (NLM), which
    allows the source code of a default web page to be viewed. However, the
    NLM has the sample page name passed to it through a URL containing the
    path to the file. It is possible to alter the URL to permit the contents 
    of any file on the system to be viewed even those situated outside the 
    web root. Using this method it is possible to view important 
    configuration files including the autoexec.ncf file which contains the
    remote console password.
    
    Description:
    ~~~~~~~~~~~~
    
    Netware is an Operating System developed by Novell
    (http://www.novell.com) and is used by many organisations for user file
    and print sharing. Version 5.1 of the Netware Operating system comes
    with a web server that will be installed by default.
    Included on the web server are a wide variety of sample pages that
    demonstrate the flexibility and features of the product. However, one
    sample page uses a Netware Loadable Module (NLM) called sewse.nlm to
    call a script called viewcode.jse. The viewcode.jse file is designed to
    be used to display the source code of sample files called httplist.htm
    and httplist.jse. These file names are passed as parameters to the NLM
    through a URL such as (URL may wrap):
    
    http://10.0.25.5/lcgi/sewse.nlm?sys:/novonyx/suitespot/docs/sewse/viewcode.jse+httplist/httplist.htm+httplist/httplist.jse
    
    The application checks the files being requested by requiring that the
    httplist directory is specified in the path to the files to be viewed.
    However, it is possible to traverse directories using /../ after
    httplist. The sewse.nlm module runs with sufficient permissions whereby
    it possible to traverse to any file on the file system and view the
    contents.
    There are many files that may be of interest to an attacker and these
    include:
    
    SYS:\ETC\NETINFO.CFG 		- Can contain a copy of the rconsole 
    				  password
    SYS:\SYSTEM\AUTOEXEC.NCF 	- Contains the rconsole password
    SYS:\ETC\FTPAUDIT.LOG 		- Contains valid usernames for password 
    				  guessing attempts
    
    An attacker could use the information gained to lauch further attacks or
    to gain console access using the rconsole password.
    An example of the URL used to view the autoexec.ncf is (URL may wrap):
    
    http://10.0.25.5/lcgi/sewse.nlm?sys:/novonyx/suitespot/docs/sewse/viewcode.jse+httplist+httplist/../../../../../system/autoexec.ncf
    
    There are Novell best practices which include encrypting the rconsole
    password in the autoexec.ncf file. However, there are tools available
    which can be used to break this encryption. Another Novell
    recommendation is to use a Console Screensaver which requires the admin
    password to be entered after a rconsole connection has been made.
    This issue is similar to the problem discovered with the convert.bas
    script that shipped with Netware Web Server version 2.0. This previous
    issue is recorded as Bugtraq ID 2025 and CVE-1999-0175.
    
    Tested Versions:
    ~~~~~~ ~~~~~~~~~
    Netware Web Server 5.1 
    
    Tested Operating Systems:
    ~~~~~~ ~~~~~~~~~ ~~~~~~~~
    Netware Operating System version 5.1
    
    Vendor & Patch Information:
    ~~~~~~ ~ ~~~~~ ~~~~~~~~~~~~
    The vendor of this product, Novell, was contacted via email using the 
    address listed as their 'community relations' on 20th November 2001. 
    When no reply was received to this email after nine days, another
    email was sent on 29th November 2001 to the same address, and copied 
    to 'secureat_private'. No reply from either address had been received 
    as of December 11th 2001, and therefore the vulnerability 
    is being released to Bugtraq.
      
    
    Workarounds:
    ~~~~~~~~~~~~
    A workaround involves removing all sample web pages and sample NLMs.
    
    
    Credits:
    ~~~~~~~~
    Research & Advisory: Martyn Ruks (martyn.ruksat_private)
    
    Thanks: 	B-r00t (br00tat_private)
    	 	Macavity (macavityat_private)
    		morphsta (morphat_private)
    		Blunt (bluntat_private)
    		Ant (antat_private)
    		Shlug (shlugat_private)
    		indig0 (indig0at_private)
    
    
    
    Disclaimer:
    ~~~~~~~~~~~
    All information in this advisory is provided on an 'as is'
    basis in the hope that it will be useful. Information Risk Management
    Plc is not responsible for any risks or occurrences caused
    by the application of this information.
    
    A copy of this advisory may be found at
    http://www.irmplc.com/advisories
    
    The PGP key used to sign IRM advisories can be obtained from the above
    URL, or from keyserver.net and its mirrors.
    
    =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Information Risk Management Plc. 
    http://www.irmplc.com, infoat_private
    22 Buckingham Gate 
    London 
    SW1E 6LB
    +44 (0)207 808 6420
    
    
    
    
    
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