[NT] LiteServe URL Decoding DoS

From: support@securiteam.com
Date: 11/18/02

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    From: support@securiteam.com
    To: list@securiteam.com
    Date: 18 Nov 2002 10:20:30 +0200

    The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
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      LiteServe URL Decoding DoS


     <http://www.cmfperception.com/> LiteServe is a powerful, full-featured
    Web, email and FTP server. This server software is perfect for personal
    websites or commercial sites with high traffic demands and multiple
    domains. A vulnerability in the way the program decodes URL allows remote
    attackers to cause it to crash.


    LiteServe's URL decoder has a problem handling illegal "%xx" sequences,
    such as "%.@", for example, and may produce corrupted output when such a
    sequence is used. The problem appears to be a referencing issue when the
    decode sequence does not specify a legitamite hexadecimal sequence. A
    denial of service may occur if LiteServe is passed an extremely large
    request consisting only of "%" characters. 290,259 such characters will
    cause LiteServe to freeze:

    GET /[buffer] HTTP/1.0

    After this request is processed, attempting to connect to the HTTP service
    reveals that the server is dead.

    use IO::Socket;
    $req=sprintf("GET /%s HTTP/1.0\r\n\r\n");
    print $f $req;
    undef $f;


    The information has been provided by <mailto:mattmurphy@kc.rr.com>
    Matthew Murphy.


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