What is XSS?, what can I accomplish with it?
XSS is common in search bars and comment boxes. We can then inject almost any type of scripting language into the website. Whether it be Javascript, HTML or XML. XSS is mainly directed at Javascript injection.
Most people use it to display messages on the website, redirect you to their defacement and even put cookie loggers and XSS shells on the website.
Reason Behind XSS vulnerability?
Poor PHP coding within text boxes and submission forms. They were too lazy to code it properly allowing us to inject strings into the source code, that would then give us the conclusion of what we put in since it’s also in the source code. They did not bother to filter what we type in. They allowed characters such as “>, “, /”, etc.
Types of XSS
There are three types of XSS. DOM-based, Persistent and non-persistent. If you inject some code into the website and it sticks to the website (you leave the page and come back, and it’s still there) then it is persistent. That is good. When you get non-persistent it will not stick on the website, you will only see it once. With persistent XSS you can do much more, leave messages, redirect them, etc. With non-persistent the most you can do is upload a cookie logger.
How to test for XSS vulnerabilities?
To test if the website is vulnerable to XSS we want to go to a search box and inject some Javascript. We’ve found a search box and now we want to use Javascript to alert a message so we can see if the Javascript was successfully executed.
**<*script*>alert(‘XSS’);
(Important:Please remove “*” or type the above text on search box without “*”)
Now we will see a pop up message “XSS”shown In picture
In some cases, a message might not pop up. If it doesn’t work, check the source code and have a look at the output. Most of the time the error requires you to make a little change.
“*>*alert(‘XSS’); (Important:Please remove ‘*’ or type the above text on search box without ‘*’) Now, we have found out that it is vulnerable.Lets go to next step.
deface/Hacking a webpage with XSS?
Here is the important part that explain defacing website i have methods for both persistent, and non-persistent XSS.
Persistent XSS.
First I will be starting with persistent XSS. Since it’s persistent I want to redirect my victims to a deface page. We simply just inject this some more Javascript like we did before: <*script*>window.location=”*http://yourdefacepage.com/index.html”;<*/script*> (Important:Please remove ‘*’ or type the above text on search box without ‘*’) Remember, you can always alter the code if it doesn’t work. You can do many things with XSS, you just need all the right strings. I’m only focusing on defacing, since most people just deface sites these days.
Non-persistent XSS.
Obviously we can’t redirect users with non-persistent. But with basic web-based programming knowledge we can make a cookie logger. We may also need advanced social engineering skills for people to open our cookie logger.
How to make a cookie logger?
As we know that we can run our own scripts on those website which have XSS vulnerability. We use our Keylogging script on XSS vulnerable website.
To perform this Attack we need three thigs
Xssed Site(That is a xss vulnerable site)
Webhosting sevice (Free) ==> http://www.000webhost.com/
Keylogging Script
First Of all Download the script from the below link
Now create an account in any free hosting web host that supports PHP. PHP will be used to write keystrokes on a text file.
Now open Logger.js and change the URL of your script. Default URL is http://yourwebsite.comjust Change it to your hosting URl.
Now host all these scripts on your web host.
Now find a XSS vulnerable website website and include script link like this:
Now if someone clicks on that link everything they type in on that page will go to the data.txt file. This script will capture all the keystroke and save it to the file with the help of PHP script.
If a website’s login page is vulnerable to XSS attack, this script can be used to grab passwords.
DOM-based XSS
What is DOM?
DOM is expanded as Document object model that allows client-side-scripts(Eg: Javascript) to dynamically access and modify the content, structure, and style of a webpage.
Like server-side scripts, client-side scripts can also accept and manipulate user input with the help of DOM.
Here is a very simple HTML code that accepts and writes user input using JavaScript with the help of DOM.
0 comments:
Post a Comment