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Re: EEYE: Workstation Service NetpManageIPCConnect Buffer Overflow



Hi,

this vulnerability is probably affected to MS Windows 2003 Server with all 
hotfix..

we have several live and testing servers in then world and on all server are 
some situation

1) workstation service doesn't working or restart automaticly after few hours..
2) servers are fully firewalled and secured but only port 80 a 3389 is allowed 
on firewall
3) server have started Terminal Services Licensing service..
4) Application log on this server can't be opened. mmc.exe fall after click 
application log without error message..

some problems are reported on our customers..

what's that.. New bug or zero day exploit for 2003 servers?



eA> eEye Research - http://research.eeye.com

eA> Workstation Service NetpManageIPCConnect Buffer Overflow

eA> Release Date:
eA> November 14, 2006

eA> Date Reported:
eA> July 25, 2006

eA> Severity:
eA> High (Remote Code Execution)

eA> Vendor:
eA> Microsoft

eA> Systems Affected:
eA> Windows 2000 (Remote Code Execution)
eA> Windows XP SP1 (Local Privilege Escalation)

eA> Overview:
eA> A flaw exists in a default Windows component called the "Workstation
eA> Service" that when exploited allows for remote code execution in SYSTEM
eA> context, allowing an attacker to take complete control of affected
eA> systems.

eA> Technical Details:
eA> In the Workstation Service module called wkssvc.dll, the
eA> NetpManageIPCConnect function has a call to "swprintf" with an unchecked
eA> buffer. The input buffer is controllable by the remote attacker.

eA>     .text:76781D67         mov     edi, [ebp+arg_0]
eA>     ...
eA>     .text:76781D90         lea     eax, [ebp+var_2CC]
eA>     ...
eA>     .text:76781DA0         push    edi
eA>     .text:76781DA1         push    offset "%ws\\IPC$"
eA>     .text:76781DA6         push    eax
eA>     .text:76781DA7         call    ds:swprintf

eA> This function is called by NetpJoinDomain, which is eventually called by
eA> the NetrJoinDomain2 function, which is exposed through RPC.

eA> The IDL for NetrJoinDomain2 looks like this:
eA> long  _NetrJoinDomain2@28 (
eA>         [in][unique][string] wchar_t * arg_1,
eA>         [in][string] wchar_t * arg_2, 
eA>         [in][unique][string] wchar_t * arg_3,
eA>         [in][unique][string] wchar_t * arg_4,
eA>         [in][unique] struct_C * arg_5,
eA>         [in] long arg_6
eA> );

eA> arg_2 will contain string with format like <Domain name>+"\"+<Hostname>.

eA> <Hostname> will be passed as NetpManageIPCConnect's first argument. The
eA> variable is under the attacker's control and is passed to swprintf,
eA> which causes a stack-based buffer overflow.

eA> For this vulnerable code to be reached, we must provide a valid and live
eA> <Domain name> as a part of the string. We can set up a fake domain
eA> server anywhere reachable from the vulnerable machine on the Internet.

eA> P.S. If you despise Birkenstocks, are not afraid of your Tequila, and
eA> are well versed in reverse engineering, bug finding, or are looking to
eA> learn, we are hiring both junior and senior security researchers. Send
eA> your resume (blathering of college course work, degrees, and past
eA> experience we don't care about) or more importantly a description of why
eA> you would be a good researcher to skunkworks@xxxxxxxxx

eA> Credit:
eA> Discovery: JeongWook Matt Oh
eA> Additional Research: Derek Soeder

eA> Related Links:
eA> Retina Network Security Scanner - Free Trial
eA> Blink Endpoint Vulnerability Prevention - Free Trial

eA> Greetings:
eA> Dugsong, Ohhara, Ryan Lee, Pilot, Sakai, Gonan and all the Korean
eA> Bugtruck Mailing List Subscribers

eA> Copyright (c) 1998-2006 eEye Digital Security
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eA> alert@xxxxxxxx for permission.

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eA> information.  In no event shall the author be liable for any direct or
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eA> user's own risk.



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