XSS Scanner
About this tool
This scanner helps you test if the target web application is affected by Cross-Site Scripting vulnerabilities.
Cross-Site Scripting (XSS) is one of the most well-known web application vulnerabilities. It even has a dedicated chapter in the OWASP Top 10 project and it is a highly chased vulnerability in bug bounty programs.
The risk of a Cross-Site Scripting vulnerability can range from cookie stealing, temporary website defacement, injecting malicious scripts, or reading sensitive page content of a victim user.
The scanner works in two steps:
1. Spider the target: In this first step, the tool tries to identify all the pages in the web application, including injectable parameters in forms, URLs, headers, etc.
2. Test for XSS: For each page discovered in the previous step, the scanner will try to detect if the parameters are vulnerable to Cross-Site Scripting and report them on the results page.
The table below shows the differences between the Light scan and the Deep scan:
Scanner capabilities | Light scan | Deep scan |
|---|---|---|
Spider max URLs | 20 | 500 |
Spider max duration | 1 minute | 15 minutes |
Active scan max duration | 2 minutes | 30 minutes |
The XSS scanner generates HTTP requests which can be flagged as attacks on the server-side (although they are harmless). Do not use it if you don't have proper authorization from the target website owner.
Parameters
Target URL: This is the URL of the website that will be scanned. All URLs must start with http or https.
Light Scan: This scan is faster but less comprehensive than the deep scan.
Deep Scan: This is a complete Cross-Site Scripting assessment of the target web application.
How it works
Our XSS Scanner uses the detection and crawling engine from our in-house website scanner. This engine has a low false positive rate and is actively maintained and improved by our team.
XSS detection is performed with a couple of requests. First, the scanner injects a simple string in the tested parameter and checks if it is reflected on the response page. If the parameter is reflected, then the scanner will inject a piece of JavaScript code, including some special HTML characters (>, <, ", ') and it will try to see if they are returned in the response page without sanitization. If this is true, the page and parameter are declared vulnerable.
More information about Cross-Site Scripting and how to remediate this vulnerability can be found on the dedicated OWASP XSS Page.