Re: Web servers / possible DOS Attack / mime header flooding

From: Daniel Leeds (dleedsat_private)
Date: Thu Sep 03 1998 - 14:51:42 PDT

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    however some other 3rd party products appear vulnerable.
    
    UnityMail 2.0 for 95/NT *IS* vulnerable to the DOS.  CPU load forks to 100%,
    the system is useable, however all access to the UnityMail administrative web
    server is hung.
    
    The above is probably not a huge deal, other than annoying mailing list admins
    who want to access their lists via the web admin, but i think its probably
    illustrative of a wider scope---> how many other administrative web interfaces,
    commercial http servers, etc are vulnerable to this denial of service?
    
    
    On 03-Sep-98
    Rich Wood wrote:
    > On 3 Sep 98, at 12:34, Laurent FACQ wrote:
    >> #       => by sending a crazy amount of 8000 bytes headers, it's possible
    >> #       to consume a lot of memory (and of course CPU). The point
    >> #       is that httpd daemons grow and STAY at this big size (or die
    >> #       if you send too much)
    >
    > Tried against apache 1.3.1 on FreeBSD 2.2.6 (DX2-66 16Mb), script hung
    > after 2500 headers with apache using 30Mb.
    >
    > Tried against apache 1.3.1 on NT4 (workstation) SP3 (P200 64Mb), after
    > 7500 headers, apache was using 120Mb RAM and the box ground to a halt.
    >
    > It didn't actually crash apache on either box, but severely reduced the
    > usefulness of the systems.
    >
    > Rich
    > --
    > Rich Wood
    
    
    
    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    Daniel Leeds                          Systems Administrator
    dleedsat_private                          DigitalFacades
    -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    



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