Web Pentesting Reflected XSS

“
Web Pentesting Reflected XSS

Reflected XSS (Cross-Site Scripting) is a type of vulnerability that occurs when user input is not properly validated or sanitized by a web application and is then reflected back to the user in the response. An attacker can exploit this vulnerability by injecting malicious scripts into the user's input, which can be executed by the user's browser when the response is rendered.

To perform a web pentesting for reflected XSS, you can follow these steps:

Step 1: Identify the input fields in the web application that may be vulnerable to XSS. This can include search boxes, contact forms, login forms, and other input fields.

Step 2: Enter some basic HTML tags into the input fields and submit the form. If the application reflects the input back to you, check to see if the HTML tags are rendered in the response. If they are, this could indicate a potential XSS vulnerability.

Step 3: Try injecting some simple JavaScript code, such as an alert box or a cookie-stealing script, into the input fields and submit the form. If the JavaScript code is executed when the response is rendered, this is a clear indication of an XSS vulnerability.

Step 4: If the application uses input validation or filtering, try bypassing it by encoding your input or using different characters to evade detection. For example, you can try using HTML entities, URL encoding, or Unicode characters to bypass filters.

Step 5: Use a web proxy or browser extension to intercept and modify the HTTP requests and responses. This can help you better understand how the application is handling user input and how it may be vulnerable to XSS.

Step 6: Once you have identified a potential XSS vulnerability, try exploiting it by injecting more complex JavaScript code or by attempting to steal sensitive data from the user, such as cookies or session tokens.

Step 7: Finally, report your findings to the web application owner or administrator and provide them with a detailed explanation of the vulnerability and its potential impact. Make sure to include any steps you took to reproduce the vulnerability and any proof-of-concept code or screenshots that demonstrate the issue.