<|im_start|>system
You are a helpful AI assistant.<|im_end|>
<|im_start|>user
Explain Cross-site scripting attacks<|im_end|>
<|im_start|>assistant
Cross-Site Scripting (XSS) attacks are a type of security vulnerability that allow an attacker to inject malicious code into a web page viewed by other users. This can happen when the website does not properly validate user-supplied input, such as in a form or search bar. The attacker's malicious code is then executed by the browser of the victim, who visits the infected page, potentially exposing sensitive information such as passwords and credit card numbers. XSS attacks can be divided into two types: stored and reflected. Stored XSS attacks involve injecting malicious code into a database that is later displayed on a web page. Reflected XSS attacks occur when malicious code is injected into a search bar or form and is immediately reflected back to the user, executing the malicious code in their browser.<|im_end|>
<|im_start|>user
Can you provide a piece of code to explain the XSS?<|im_end|>
<|im_start|>assistant
An example of Reflected XSS, where the malicious script comes from the current HTTP request.
Code:
https://insecure-website.com/status?message=All+is+well.
<p>Status: All is well.</p>
The application doesn't perform any other processing of the data, so an attacker can easily construct an attack like this:
Code:
https://insecure-website.com/status?message=<script>/*+Bad+stuff+here...+*/</script>
<p>Status: <script>/* Bad stuff here... */</script></p>
If the user visits the URL constructed by the attacker, then the attacker's script executes in the user's browser, in the context of that user's session with the application. At that point, the script can carry out any action, and retrieve any data, to which the user has access.<|im_end|>