Certified Information Systems Auditor (CISA) — Question 317

The MOST critical security weakness of a packet level firewall is that it can be circumvented by:

Answer options

• A. deciphering the signature information of the packets
• B. using a dictionary attack of encrypted passwords
• C. intercepting packets and viewing passwords sent in clear text
• D. changing the source address on incoming packets

Correct answer: D

Explanation

The correct answer, D, indicates that altering the source address can allow an attacker to bypass the firewall's filtering rules. Options A, B, and C do not directly relate to the fundamental operation of packet filtering, which primarily inspects header information rather than the payload content or encryption of packets.