KPMG-2002004: Lotus Domino Webserver DOS-device Denial of Service

From: Peter Gründl (pgrundlat_private)
Date: Mon Feb 04 2002 - 05:58:55 PST

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          -=>Lotus Domino Webserver DOS-device Denial of Service<=-
                          courtesy of KMPG Denmark
    
    BUG-ID: 2002004          Released: 4th Feb 2002
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    Problem:
    ========
    The Domino Webserver does not handle URL request for DoS-Devices
    correctly. This vulnerability can be exploited by a malicious user
    to bring down the webserver.
    
    Vulnerable:
    ===========
    - Lotus Domino Webserver prior to 5.0.9a on Windows 2000
    
    Details:
    ========
    there are two issues in the Domino Webserver that give similar
    results when exploited.
    
    First issue)
    A request for a DOS-device from CGI-BIN with any given extension
    is accepted by the server as a valid request and is passed on
    the to cgihandler (nhttpcgi.exe). Due to the nature of DOS-
    devices (CON, AUX, PRN etc.) the process never releases the file
    again, and when Domino's limit of 400 working threads has been
    reached, the server will no longer accept requests.
    
    Second issue)
    Requesting a DOS-device (eg. NUL) from CGI-BIN with an extension
    of 220 chars (eg. 220x"a") results in the server spawning
    cmd.exe to run, in this case, nul.pif. The server will then pop
    up a window, asking which file you want to open nul.pif with.
    This can be done 400 times, before the server runs out of
    working threads or less, if it runs out of memory, since this
    attack opens up a lot of processes.
    
    Vendor URL:
    ===========
    You can visit the vendors webpage here: http://www.lotus.com
    
    Vendor response:
    ================
    The vendor was contacted on the 1st of November, 2001. On the 5th
    of November the vendor confirms that they have reproduced the issues
    on Windows 2000. The issues were assigned bug id: JCHN4UMKLA and
    JCHN547JWV by the vendor. On the 4th of January, 2002, it was
    confirmed that the patch corrected the two issues mentioned in this
    advisory.
    
    Corrective action:
    ==================
    Upgrade to Domino 5.0.9a, which can be downloaded here:
    http://notes.net/qmrdown.nsf
    
    
       Author: Peter Gründl (pgrundlat_private)
    
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    through our security advisories. These advisories are a service to
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    ble for any consequences whatsoever arising out of or in connection
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