Which firewall examines all incoming requests against known vulnerabilities and only allows requests that are deemed genuine to pass?

Which firewall examines all incoming requests against known vulnerabilities and only allows requests that are deemed genuine to pass?

• A. NAT
• B. Packet Filtering Firewall
• C. Stateful Multilayer Inspection Firewall
• D. Active Application-Level Firewalls

Answer: (D)

Focusing on application-layer defense, this type of firewall performs deep inspection of the actual application requests and uses knowledge of known vulnerabilities to decide what passes. It doesn’t just look at where a packet came from or its basic headers; it analyzes the content against vulnerability signatures and behavioral rules for the application, blocking anything that looks exploitative and allowing requests that are legitimate. That capability to assess requests in the context of the application and apply signatures to reject malicious traffic is what makes it the best fit. NAT, by contrast, is about translating IP addresses and ports, not inspecting content. A packet-filtering firewall checks only header information like IPs and ports, without examining the payload for vulnerabilities. A Stateful Multilayer Inspection firewall tracks connection state and can inspect traffic more deeply than a simple packet filter, but it doesn’t inherently rely on a vulnerability-signature database to filter out known exploits at the application level.

Focusing on application-layer defense, this type of firewall performs deep inspection of the actual application requests and uses knowledge of known vulnerabilities to decide what passes. It doesn’t just look at where a packet came from or its basic headers; it analyzes the content against vulnerability signatures and behavioral rules for the application, blocking anything that looks exploitative and allowing requests that are legitimate. That capability to assess requests in the context of the application and apply signatures to reject malicious traffic is what makes it the best fit.

NAT, by contrast, is about translating IP addresses and ports, not inspecting content. A packet-filtering firewall checks only header information like IPs and ports, without examining the payload for vulnerabilities. A Stateful Multilayer Inspection firewall tracks connection state and can inspect traffic more deeply than a simple packet filter, but it doesn’t inherently rely on a vulnerability-signature database to filter out known exploits at the application level.