Web application firewalls (WAFs) help prevent which application layer attack?XSSSQL InjectionDDOSAll of the above

1. Break Down the Problem

The question is asking which type of application layer attack can be prevented by Web Application Firewalls (WAFs). We have four options:

1. XSS (Cross-site Scripting)
2. SQL Injection
3. DDoS (Distributed Denial of Service)
4. All of the above

2. Relevant Concepts

Web Application Firewalls are designed to protect web applications by filtering and monitoring HTTP traffic. They are particularly effective against various application layer attacks, especially those targeting the web application layer.

• XSS (Cross-site Scripting): An attack that allows attackers to inject malicious scripts into content that other users will view.
• SQL Injection: An attack that targets the database layer by injecting malicious SQL code into a query.
• DDoS (Distributed Denial of Service): A malicious attempt to disrupt normal functioning of targeted servers, usually by overwhelming them with traffic.

3. Analysis and Detail

• WAFs can effectively mitigate XSS by filtering out harmful scripts.
• They are also capable of detecting and preventing SQL injection attempts since it's a common web application vulnerability.
• DDoS attacks, while not application-specific, can be mitigated by WAFs through rate limiting, traffic shaping, or detecting unusual traffic patterns.

4. Verify and Summarize

Since WAFs can protect against both XSS and SQL Injection and have capabilities to mitigate DDoS attacks, the correct answer must encompass all three options.

Final Answer

All of the above.