Skip to main content

Hi ClearClick! Good bye Clickjacking?


Javascript is not necessarily needed to execute Clickjacking.JavaScript might make the attacker’s life easier, but it’s not inevitable to make the attack. Alternatively the attacker can use frame tags to load any site of their choice in the background and using another div tag redirect the user to any other site of choice. No role of Javascript here. Mitigation? Don't load frame in your browser in any case. all it takes is including this piece of javascript in your page:


This works in most browsers, with Internet Explorer being a notable exception.
IE8 comes with another new technique.The fix is actually very simple: it lets website owners include an extra tag in their pages that tells Internet Explorer the page is not supposed to be included in a frame. It’s called X-FRAME-OPTIONS;
a value of DENY means the page should never be opened in a frame, and
SAMEORIGIN only allows it to be framed within pages from the same site.
Any other use will show a warning, and a link that opens the page in a
new screen.
There are efforts to make Firefox too compatible to it .

But for the time being, Firefox users can use the a plug in ClearClick by NoScript.
Default protections that NoScript has provided for a long time, i.e. JavaScript and plugin blocking can prevent most clickjacking attacks. In older version, though, to be 100% protected against Clickjacking you needed to enable the Forbid IFRAME and possibly Apply these restrictions to trusted sites as well NoScript options.
Fortunately, since version 1.8.2, NoScript provides a new default kind of protection called ClearClick, which defeats clickjacking no matter if you block frames or not . Even better, ClearClick can protect you from Clickjacking / UI-redressing attack independently from JavaScript and plugins blocking: you can even Allow scripts globally (which is not recommended anyway), and your ClearClick still works.

Clickjacking hides or displaces or partially covers something you wouldn't want to click, if you could see it in its original context. ClearClick does the opposite: whenever you click a plugin object or a framed page, it takes a screenshot of it alone and opaque (i.e. an image of it with no transparencies and no overlaying objects), then compares it with a screenshot of the parent page as you can see it. If the two images differ, a clickjacking attack is probably happening and NoScript raises a "ClearClick warning",

Comments

Popular posts from this blog

Ardilla- New tool for finding SQL Injection and XSS

Three Researchers -- MIT's Adam Kiezun , Stanford's Philip Guo , and Syracuse University's Karthick Jayaraman -- has developed a new tool ' Ardilla ' that automatically finds and exploits SQL injection and cross-site scripting vulnerabilities in Web applications. It creates inputs that pinpoint bugs in Web applications and then generates SQL injection and XSS attacks. But for now Ardilla is for PHP -based Web app only. The researchers say Ardilla found 68 never-before found vulnerabilities in five different PHP applications using the tool -- 23 SQL injection and 45 XSS flaws. More information is awaited. For their attack generation techniques refer to their document at: http://www.cs.washington.edu/homes/mernst/pubs/create-attacks-tr054.pdf

Combining power of Fiddler with Burp

Both are pretty powerful tools when it comes to intercept and modify http communications. But at some point of time, they become even more powerful combo if tied with each other. They complement each other. In a recent pentest I came across a similar situation where in Burp was not able to intercept a specific kind of traffic and Fiddler came to rescue. The application was designed to upload video. The initial communication was straight forward, I mean logging into application, filling up the video details etc. And all these were easily captured by Burp except the point where you hit the Upload Video and it connects to a different server and surprisingly it was not captured by Burp, not sure why, even after repeated attempts. So, I fired Fiddler to see if the it sees this request. But it's a;ways to play with requests using Burp due to it's various functionalities like, Intruder, Repeaters etc. But it was necessary to capture this request in Burp. So the below steps can be

File Upload through Null Byte Injection

Sometimes, during file upload we come across situation wherein there would be check on the file extension at the client side as well as server side too. If the application does allow only .jpeg extension to be uploaded, the client side java script checks for the extension of the file before passing the request. We all know that how easily this can be defeated. Some applications, checks for the extension at the server side also. That's not easy to bypass. However there are some ways with which it still can be bypassed. Most of server side scripts are written in high level languages such as Php, Java etc who still use some C/C++ libraries to read the file name and contents. That leads to the problem. In C/C++ a line ends with /00 or which is called Null Byte. So whenever the interpreter sees a null byte at the end of the a string, it stops reading thinking it has reached at the end of the string. This can be used for the bypass. It works for many servers, specially php servers. T