Greetings, today's topic is the "XSS" vulnerability.
What is the vulnerability caused by:
1. Insecure data input: The direct use of user-supplied data in a web application without validation or filtering can lead to an XSS vulnerability. Attackers attack these data inputs by injecting malicious JavaScript code.
2. Lack of correct output coding: Failure to correctly encode the output of the web application can cause the browser to correctly interpret the malicious code injected by the attacker. In this case, the browser will recognize the malicious code as safe content and execute it.
3. Unsafe browser behavior: Some browsers may have security vulnerabilities or may not provide adequate protections against XSS attacks by default. In this case, attackers can perform XSS attacks by targeting the vulnerabilities of these browsers.
Types:
2. (Stored) XSS: This type of XSS attack occurs when the data provided by the user is stored on the server and made available to other users. For example, a message posted by a user on a forum may contain malicious code when being displayed to other users. This type of attack can occur in web applications where data is stored on the server and presented to other users.
3. DOM XSS: This type of XSS attack occurs on the Document Object Model (DOM) dynamically generated by JavaScript. In web applications, operations are performed on the DOM structure, which is created and modified by JavaScript code. In this case, a malicious code can take effect when it is rendered on the DOM by the web application's JavaScript code.
4. Self-XSS: This type of attack tricks users into voluntarily copying and pasting malicious code. The attacker uses social engineering tactics to trick the user into copying and pasting malicious code. When the user executes the copied code, the XSS attack occurs.
5. Blind XSS: This type of attack allows a malicious attacker to perform an XSS attack without receiving feedback on the server side. The attacker sends a malicious request to the server and an XSS attack occurs on the server side. However, it is not possible for the attacker to receive feedback from the server or see the result.
6. Document Type XSS: This type of XSS attack occurs during doctype definition. The attacker injects malicious codes in the doctype definition section at the beginning of the web page and when these codes are processed by the browser, the XSS attack occurs.
7. Mutation XSS: This type of attack allows a malicious attacker to perform an XSS attack by modifying the source code of an existing web page. The attacker injects malicious code by modifying the source code of the web page, and when this code is processed by the browser, the XSS attack occurs.
8. Browser Extension XSS: This type of attack is an XSS attack where browser plugins or extension galleries are exploited by a malicious attacker. The attacker can exploit vulnerabilities in a browser extension or extension gallery to spread malicious code, which is then rendered by the browser, resulting in an XSS attack.
10. sudo XSS (Super User Do) refers to when a malicious attacker uses the administrator or super user (root) privileges of a web application to perform an XSS attack. In this type of attack, the attacker injects malicious code by gaining access to the web application's admin panel or super user (root) privileges, and when this code is processed by the browser, the XSS attack occurs. Sudo XSS can be more dangerous than regular XSS attacks because the attacker can do more damage or take over the system completely because they have more privileges.
