Preventing Attacks with Output Encoding

B.

Output encoding is a technique used to prevent certain types of attacks, such as cross-site scripting (XSS), which involves injecting malicious code into a website. Output encoding can be done using a variety of methods, such as HTML entity encoding, URL encoding, and JavaScript encoding.

Out of the given options, the attack that can be prevented by using output encoding is Cross-site scripting (XSS), which is option B. XSS is a type of attack where an attacker injects malicious code into a web page that is then executed by unsuspecting users. The malicious code can be used to steal user data or perform other malicious actions.

Output encoding can prevent XSS by converting characters in user input into their encoded equivalents. For example, the "<" character can be converted to "<", which is the HTML entity equivalent. By doing this, the web application can prevent malicious code from being executed by the user's browser.

The other attacks mentioned in the options such as server-side request forgery, SQL injection, command injection, cross-site request forgery, and directory traversal can be prevented by other security techniques such as input validation, access controls, and secure coding practices.

In summary, output encoding can prevent Cross-site scripting (XSS), but it may not be effective against other types of attacks. It is important to use a combination of security techniques to protect web applications from various types of attacks.