Re: CounterStrike (HalfLife?) Server possible DoS attack.

From: Stanley G. Bubrouski (stanat_private)
Date: Fri Nov 29 2002 - 16:22:41 PST

  • Next message: Bruno Mosconi: "Lotus NOTES"

    The 'nextmap' chat command is an Admin-Mod command
    and not a built-in Counter-Strike or Half-life command.
    Furthermore, if an anti-flood plugin is installed, such
    as the one that comes with Admin-Mod it must be the
    first plugin listed in Admin-Mod's plugins.ini or else
    the other plugins will interpret what is sent first
    rendering the anti-flood plugin useless.
    
    There was a bug in Half-Life Dedicated Server (HLDS)
    which would cause the service to crash if certain
    commands were flooded to the server.  This bug was
    fixed in HLDS 3.1.1.0b and 4.1.1.0b beta builds of
    HLDS available at files.valve-erc.com (password
    required, you can find it in hlds hlds_linux
    mailling list archives.)  This beta update came out
    May 11, 2002 so its been out there a long time and
    most servers are using it.
    
    So for clarification:
    1) This issue is not new, it has been discussed on
    the HLDS and HLDS_LINUX ML.
    2) A patch has been available since early May.
    3) Even without the patch, if a proper anti-flood
    plugin is installed correctly its not an issue.
    4) There have been exploit scripts available for
    these bugs (including this one) for over a year.
    5) The reporter of this bug ought to be banned
    from HL for using scripts for the purpose of
    causing denial-of-service attacks (he most likely
    learned of the attack from the many websites that
    describe or from cheat software that have such
    exploits built-in.
    
    
    -Stan Bubrouski
    
    
    On Thu, 28 Nov 2002, hellNbak wrote:
    
    > Dude don't mess with my fraggin counterstrike.  :-)
    >
    > Tested on latest version with all patches and it doesn't work.  But if I
    > remember correctly the patch was on the server side so mileage may vary.
    >
    > On Thu, 28 Nov 2002, Patrick Webster wrote:
    >
    > > Date: Thu, 28 Nov 2002 11:12:24 +1100
    > > From: Patrick Webster <webster_pat_private>
    > > To: "SF-Vuln-Dev (E-mail)" <vuln-devat_private>
    > > Subject: CounterStrike (HalfLife?) Server possible DoS attack.
    > >
    > > Hi Guys,
    > >
    > > Could someone who actually has CounterStrike on their PC look into this for
    > > me and see if it still exists?
    > > Last I remember, it was possible to crash a CS server and thus disconnect
    > > all users by requesting "say nextmap" multiple times.
    > > To reproduce this attack, you simply bind any key to ask the server to
    > > display the next map - I recall it as 'say nextmap'.
    > > So, for example;
    > >
    > > F6 = 'say nextmap; say nextmap; say nextmap; say nextmap; say nextmap; say
    > > nextmap; say nextmap; say nextmap; say nextmap; say nextmap; say nextmap'
    > >
    > > Connect to a server, and rapidly press F6 until you are disconnected. Try
    > > and reconnect - the service should have crashed.
    > >
    > > Thanks,
    > >
    > > Patrick Webster,
    > > Systems Administrator
    > >
    > > DeMorgan Information Security Services
    > >
    > > Freecall: 1800 DE MO RG (33 66 74)
    > > Tel: +61299290377
    > > Fax: +61299290917
    > > Mob: +61403421390
    > >
    > > Address: Level 2, 41 McLaren St
    > > North Sydney, NSW, 2060, Australia
    > >
    > > Visit us at: www.demorgan.com.au
    >
    > --
    > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    >
    > "I don't intend to offend, I offend with my intent"
    >
    > hellNbakat_private
    > http://www.nmrc.org/~hellnbak
    >
    > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
    >
    



    This archive was generated by hypermail 2b30 : Sun Dec 01 2002 - 12:42:26 PST