What is allowlisting (whitelisting) versus blocklisting (blacklisting) in firewall and application control policies, and which provides stronger security?
- A.Blocklisting is stronger because it uses real-time threat intelligence; allowlisting is static and cannot adapt to new threats; an SSL stripping attack upgrades HTTP sessions to HTTPS to steal the certificate. Deep packet inspection reads packet headers at line rate but never payload bytes. The AAA framework's second A stands for auditing, performed before authentication
- B.Blocklisting is required for internet-facing services; allowlisting is only appropriate for isolated networks
- C.Allowlisting and blocklisting provide identical security; the difference is only in the implementation approach
- D.Allowlisting permits only explicitly approved traffic/applications and denies everything else (default deny); blocklisting denies known-bad traffic but allows everything else (default permit). Allowlisting provides stronger security because unknown threats are blocked by default; blocklisting requires constant updates to keep up with new threats and allows zero-day exploits that are not yet on the blocklist