XSS found in Linkbucks.com

Linkbucks.com website was found to be vulnerable to Cross Site Scripting(XSS) vulnerability, which could be exploited using malicious scripts.


Vulnerability Description:
==================
Linkbucks.com is a famous advertising network site that brings web users, websites and marketers together. The XSS vulnerability is found in the Default.aspx page. Script can be injected to the Message and Returnurl parameters. This can be exploited by injecting arbitrary HTML and malicious script code, which will execute in a user's browser session. Unvalidated redirection and forwarding is also possible.

Vulnerability testing:
===============
Vulnerable URL: http://www.linkbucks.com/Default.aspx?
Tested with: Firefox 3.5 and Internet Explorer 7 on Windows XP SP3

A simple "alert("You are hACked by w01f")" script was injected to the "Default" page. It was executed and display on the web browser. Malicious script could be executed using this method.



Exploit Code using "alert": Download

- Update on 19 Aug

Below is the video demonstration on exploiting the XSS vulnerability using redirection. It will redirect to my blog. Hacker can redirect to a spoofed Linkbucks site with malicious code.



Exploit Code using redirection: Download

Remediation:
==========
The Message and ReturnURL parameters need to be properly sanitized after a user's logging out. The Linksbuck support team was contacted on the vulnerability. The support ticket is "#KHT-97974-227" but so far no fixed was done.

DOS vulnerability on Internet Browser

While contributing to the OSVDB. I notice about the recent DoS (Denial of Service) vulnerability on the Internet Browser and decided to research on it.

Internet Browser such as IE and Firefox contains a flaw that may allow a remote denial of service. The vulnerability can be triggered when processing a web page with a large number of various invalid request such as NNTP, NEWS and Mailto. This may cause the system to crash due to high resources consumption.

I have tested on some of these exploits. Test at your own risk.

Affected Browser: Internet Explorer, FireFox, Chrome, Opera, etc
OSVDB: 65110
Exploit Code: Download

Wing FTP Server - Cross Site Scripting Vulnerability

The Wing FTP Server was found to be vulnerable to Cross Site Scripting(XSS) vulnerability, which could be exploited using malicious scripts.

Discovered Date: May 31, 2010
System affected: Wing FTP Server for Windows, Version 3.5.0 and prior version
Discovered by: w01f

Vulnerability Description:
==================
Wing FTP server is a multi-protocol file server, which support such as HTTP and FTP. It comes with a Web-based "Administrator" Console. The XSS vulnerability is found in the "Administrator" Web interface . It is accessible using the server IP with default port 5366 (Eg. http://192.168.0.1:5466). Script can be injected to the "POST" command. This can be exploited by injecting arbitrary HTML and malicious script code, which will execute in a user's browser session.

Vulnerability testing:
===============
Vulnerable URL: http://192.168.41.137:5466/admin_loginok.html
Tested with: Firefox 3.5 and Internet Explorer 7 on Windows XP SP3
with Web proxy

In the "Administrator" web interface, from the login page, a simple "alert("You are HACKed!")" script was injected to the "POST" command. It was executed and display on the web browser. Malicious script could be executed using this method.

Remediation:
==========
Discussion with the wftpserver.com support. This vulnerability was not consider critical as it requires authenticated login to exploit. But it will be fixed on the next release in about a month time.

Updated 10 Jun 2010:
The flaw was fixed on version 3.5.1.

References:
- Common Vulnerabilities and Exposures: CVE-2010-2428
- National Vulnerability Database (CVE-2010-2428)
- ISS X-Force Database: wingftpserver-adminloginok-xss (59094)
- SecurityFocus: Wing FTP Server 'admin_loginok.html' HTML Injection Vulnerability
- OSVDB 65444 : Wing FTP Server Admin Interface admin_loginok.html XSS
- SANS: @RISK: The Consensus Security Vulnerability Alert
- Bugtraq: Wing FTP Server - Cross Site Scripting Vulnerability
- Packet Storm: wingftp-xss.txt

XSS vulnerability found on D-Link Router

Cross Site Scripting (XSS) vulnerability was found on the D-Link DI-724P+ Router, which can be exploited by conducting a cross-site scripting attacks.

Discovered Date: May 14, 2010
System affected: D-Link DI-724P+ Router, Firmware Version: v1.03
Discovered by: w01f

Vulnerability Description:
==================
The XSS vulnerability is found in the Admin Web interface. It is accessible using http://192.168.0.1 (by default). Script can be injected from the GET string. This can be exploited by injecting arbitrary HTML and malicious script code, which will execute in a user's browser session.

Vulnerability testing:
===============
Vulnerable URL: http://192.168.0.1/wlap.htm
Tested with: Windows XP with Internet Explorer 7, using Web proxy

In the Admin web interface, under the "wireless" tab, i injected a simple "alert("You are hack!")" script in the GET string. It was executed and display on the web browser.

Remediation:
==========
According to D-Link, the router is out of support and will not be releasing any patches. Continue using on your own risk.

References:
- SecurityFocus: D-Link DI-724P+ Router 'wlap.htm' HTML Injection Vulnerability
- OSVDB 65002 : D-Link DI-724P+ Admin Interface wlap.htm GET String XSS
- SANS: @RISK: The Consensus Security Vulnerability Alert
- Packet Storm: dlinkdi724p-xss.txt
- Full Disclosure: D-Link DI-724P+ Router - Cross Site Scripting Vulnerability

Adobe new vulnerbility APSA09-07, CVE-2009-4324

Adobe had recently confirmed a critical vulnerability in Adobe Reader and Acrobat 9.2 and earlier versions that could cause a crash and potentially allow an attacker to take control of the affected system. There are reports that this vulnerability is being actively exploited in the wild.

This vulnerability affects Adobe Reader/Acrobat 9.2 or older. the vulnerability was found in the JavaScript function specific when reading PDF file. Exploits were found in the form of maliciously crafted PDF files.

Exploits Behaviours:
==============
It drops and execute a malicious downloader. This downloader will download more malwares from domain such as foruminspace.com.

Other symptoms such as unexpected network connections from the Adobe Reader and in some cases, Adobe reader may crashes or terminates abnormally.

From my observation, major AV vendors such as Symantec, Sophos, McAfee, TrendMicro had specific signatures for this exploit. Not sure if other AV such as Panda or Kaspersky, which do not have a specific signature, can detect this exploit under their generic signatures. I have requested for a copy of the malware from a McAfee researcher. Hopefully can get it to do a further analysis.

So far the findings from McAfee, the malware uses JavaScript obfuscation to hide the actual exploit code in the malicious PDF.

Example of a sample code that shows the malware using XOR encoder to hide the exploit code.

s1='\x2a\x3d\x3e\x \x31\x \x31\x33\x \x25\x67\x56\x \x35\x3a\x7\x .....';

s2='';
for (i=0; i< s1.length; i++)
{

s2=s2+String.fromCharCode(s1.charCodeAt(i) ^ k);

};

eval(s2);

The patch for this vulnerbility was announced to be release next year, but user can mitigate this problem by disabling JavaScript in Adobe Reader and Acrobat. Please refer to "Disable javascript in Adobe Acrobat" or Adobe security bulletin for the steps.