Ethical Hacking Questions
Cross-site scripting (XSS) is a type of security vulnerability that occurs when an attacker injects malicious scripts into a trusted website or web application. This vulnerability allows the attacker to bypass the same-origin policy, which is a security measure that prevents scripts from one website accessing or modifying content on another website.
There are three main types of XSS attacks:
1. Stored XSS: In this type of attack, the malicious script is permanently stored on the target website's server, such as in a database or comment section. When a user visits the affected page, the script is executed, allowing the attacker to steal sensitive information or perform unauthorized actions on behalf of the user.
2. Reflected XSS: In this attack, the malicious script is embedded in a URL or input field, and when the user interacts with it, the script is executed. The script is not permanently stored on the server, but rather reflected back to the user's browser from a trusted website. This type of attack often occurs through phishing emails or malicious links.
3. DOM-based XSS: This type of attack exploits vulnerabilities in the Document Object Model (DOM) of a web page. The attacker manipulates the DOM to inject and execute malicious scripts, which can lead to unauthorized actions or data theft.
To prevent XSS attacks, developers should implement proper input validation and output encoding techniques. This includes sanitizing user input, validating and filtering data, and encoding output to prevent the execution of malicious scripts. Additionally, web application firewalls and security testing can help identify and mitigate XSS vulnerabilities.