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Re: smtpsvc and undocumented registry values
From: Thierry Haven <thierry.haven () xmcopartners com>
Date: Thu, 24 Feb 2005 11:01:27 +0100

Thanks for your answers... but I'm sorry, my question was about mail -RELAYING- through SMTP. By modyfing the banner with 
Metabase Explorer (as you said, or as established on safehack.com) it is only possible to hide the current version when 
connecting to the server thanks to telnet / port 25. However, if someone wants to do this without Metabase Explorer, here's 
another way to do it:

#cd drive:\Inetpub\Adminscripts
#cscript adsutil.vbs set smtpsvc/vsi_number/connectresponse "new banner"
(with vsi_number = the virtual SMTP server number)

In my first post, I was talking about removing the version in mail -HEADERS-... So I believe that it's not possible so 
far without patching smtpsvc.dll, which is definitively NOT a proper/clean solution.

Best Regards,

_______________________________________
Thierry Haven - Xmco Partners
Security Consulting / Pentest
web  : http://www.xmcopartners.com


Jalal, Ahmed wrote:
I came across such a trick in an Exchange book.  Basically you go into IIS
6.0 Metabase Explorer utility and locate the SMTP virtual server you want to
change (\lm\Smtpsvc\1). Then you highlight the "1" folder and click edit,
new, String Record and give it a value of 36907.  After creating that, you
highlight the newly created record, double click on it and enter the new
banner information.  Then restart the SMTP virtual server.

I have never tried it, just read it.



-----Original Message-----
From: Thierry Haven [mailto:thierry.haven () xmcopartners com] Sent: Wednesday, February 23, 2005 11:27 AM
To: Thierry Haven
Cc: full-disclosure () lists netsys com
Subject: [Full-disclosure] smtpsvc and undocumented registry values

Hi,
I've been hacking around smtpsvc.dll (Windows Server 2003) in order to hide
the Server version when a mail is relayed:

Original header:
"from [192.168.X.X] ([192.168.X.X]) by winserv2003 with Microsoft
SMTPSVC(6.0.3790.0); Wed, 23 Feb 2005 15:47:51 +0100"

I found that it is possible to remove this information by patching the code
directly in the DLL:

Modified header:
"from [192.168.X.X] ([192.168.X.X]) by winserv2003 with some server;
Wed, 23 Feb 2005 15:49:51 +0100"
... Assuming that smtpsvc.dll checks its own version at runtime by
retrieving information in the .rsrc section of the PE thanks to version.dll
calls. However I'd like to know if there is a better way to disable this
"feature" (maybe a key in the registry ?).

Next I'd like to ask about such undocumented registry values. Where to find
information about them ?


Best Regards,

_______________________________________
Thierry Haven - Xmco Partners
Security Consulting / Pentest
web  : http://www.xmcopartners.com
_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.netsys.com/full-disclosure-charter.html
_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.netsys.com/full-disclosure-charter.html


_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.netsys.com/full-disclosure-charter.html


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