To answer this question, you need to understand the role of network firewalls in preventing web application attacks.
Option A) Network firewalls cannot prevent attacks because ports 80 and 443 must be open - This option is correct. Network firewalls are designed to filter network traffic based on specific rules and policies. However, web application attacks often use legitimate ports such as port 80 (HTTP) and port 443 (HTTPS) to bypass firewall restrictions. Therefore, even if a network firewall is in place, it may not be able to prevent web application attacks if these ports are open.
Option B) If configured properly, network firewalls can prevent attacks - This option is incorrect. While proper configuration of a network firewall is important for its effectiveness, it is not guaranteed to prevent all web application attacks. As mentioned earlier, attacks that use legitimate ports can bypass firewall restrictions.
Option C) Network firewalls cannot prevent attacks because it's too complex to configure - This option is incorrect. While configuring a network firewall may require some technical knowledge, it can still be done effectively. The complexity of configuration does not necessarily mean that firewalls cannot prevent attacks.
Option D) Network firewalls can prevent attacks because they can detect malicious HTTP traffic - This option is incorrect. Network firewalls are primarily designed to filter network traffic based on rules and policies, not to detect specific types of traffic such as malicious HTTP traffic. Firewalls can block or allow traffic based on certain criteria, but they do not have the ability to detect the specific nature of the traffic.
The correct answer is A) Network firewalls cannot prevent attacks because ports 80 and 443 must be open. This option is correct because web application attacks often utilize these ports, making it difficult for network firewalls to effectively prevent such attacks.