sometimes IIS 4.0 don't write logs.

From: ThEye (theyeat_private)
Date: Wed Dec 19 2001 - 22:38:49 PST

  • Next message: Pablo Aravena: "RE: sometimes IIS 4.0 don't write logs."

    Hi:
    
    I don't know if this problem is documented but i didn't find anything about 
    it anywhere.
    
    The problem is the following one:
    
    + Problem:
    When I was playing with "Microsoft IIS and PWS Extended Unicode Directory 
    Transveral Vulnerability" ( BugtraqID = 1806 ) I found that if the attacker 
    uses the "k" option of cmd ( cmd /k ) instead of the "c" option (cmd /c) 
    ,IIS 4.0 (with Extended Unicode Directory Transveral Vulnerability) 
    sometimes don't write logs of the attacker's activity.
    
    + Implications:
    If an attacker uses this vulnerability to crack a web page or anything, 
    eventually no tracks will exist on the attacked server.
    
    + Final:
    In PROBLEM I said "sometimes" because after a high number of requests to 
    "cmd /k" , IIS 4.0 write logs of some requests, still I don't know when and 
    why IIS 4.0 write logs of the "cmd /k" request.
    Anyone that can confirm or refute this please post it.
    
    
    + Exploit:
    I tested this problem on Windows NT Server 4.0 with IIS 4.0 just installed 
    ( without any patch ).
    
    http://server.com/scripts/..%c1%pc../winnt/system32/cmd.exe?/k+dir
    http://server.com/scripts/..%c0%af../winnt/system32/cmd.exe?/k+dir
    http://server.com/msadc/..%c1%pc../winnt/system32/cmd.exe?/k+dir
    http://server.com/msadc/..%c0%af../winnt/system32/cmd.exe?/k+dir
    
    Result: No tracks on log files.
    
    + More Information:
    1) Microsoft IIS and PWS Extended Unicode Directory Transversal
        http://www.securityfocus.com/cgi-bin/vulns-item.pl?section=info&id=1806
    2) Microsoft Patch prmcan4i
        http://download.microsoft.com/download/winntsp/Patch/q269862/NT4ALPHA/EN-US/prmcan4i.exe
    
    Roberto Alamos M. (theyeat_private)
    www.350cc.com
    



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