Re: IIS 4.0 remote DoS (MS99-029)

From: Chuck Rock (carockat_private)
Date: Fri Aug 13 1999 - 13:08:50 PDT

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    Microsoft has also removed this patch becaus it was not fully regression
    tested when it was released and didn't work with some older software.
    
    They are working on a new patch that will be fully regression tested.
    
    Here is the patch removal notice from Microsoft.
    
    http://www.microsoft.com/security/bulletins/ms99-029regression.asp
    
    Chuck
    
    -----Original Message-----
    From: Bugtraq List [mailto:BUGTRAQat_private]On Behalf Of Nobuo
    Miwa
    Sent: Wednesday, August 11, 1999 5:25 PM
    To: BUGTRAQat_private
    Subject: IIS 4.0 remote DoS (MS99-029)
    
    
    Hi,
    
    I found a kind of DoS attack against IIS 4.0 on NT SP4 & SP5.
    I reported it to MS and they've provided HotFix for this.
    
    Problem Description
    -------------------
    Simple play. I sent lots of "Host:aaaaa...aa" to IIS like...
    
      GET / HTTP/1.1
      Host: aaaaaaaaaaaaaaaaaaaaaaa....(200 bytes)
      Host: aaaaaaaaaaaaaaaaaaaaaaa....(200 bytes)
      ...10,000 lines
      Host: aaaaaaaaaaaaaaaaaaaaaaa....(200 bytes)
    
    I sent twice above request sets. Then somehow victim IIS got
    memory leak after these requests. Of course, it can not
    respond any request any more.
    If you try this, you should see memory increase through
    performance monitor. You would see memory increase even after
    those requests finished already. It will stop when you got
    shortage of virtual memory.
    After that, you might not be able to restart web service and
    you would restart computer.
    I tried this against Japanese and English version of Windows NT.
    
    Fix Information
    ---------------
    MS announced in their Security Bulletin as following :
    http://www.microsoft.com/security/bulletins/MS99-029faq.asp
    
    Additional information
    ----------------------
    You'll realize someone release exploit code of this thing.
    It's easy to make it by using perl or another scripts.
    
    <Nobuo Miwa> n-miwaat_private       ( @ @ ) http://www.lac.co.jp/security
    -------------------------------o00o--(. .)--o00o-------------------------
    



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