Perfect Forward Secrecy (PFS)is a cryptographic feature inSSL/TLS key exchangethat ensures each session uses a unique key that isnot derived from previous sessions. This prevents attackers from decrypting historical encrypted traffic even if they obtain the server’s private key.
WhenSSL Inbound Inspectionis enabled on a Palo Alto NetworksNext-Generation Firewall (NGFW), the firewalldecrypts inbound encrypted trafficdestined for an internal server to inspect it for threats, malware, or policy violations.
Meddler-in-the-Middle (MITM) Role– Since PFSprevents session key reuse, the firewallcannot use static keysfor decryption. Instead, it must act as aman-in-the-middle (MITM)between theclient and the internal server.
Decryption Process–
The firewallterminates the SSL session from the external client.
It thenestablishes a new encrypted sessionbetween itself and the internal server.
This allows the firewall todecrypt, inspect, and then re-encrypt trafficbefore forwarding it to the server.
Security Implications–
This approach ensuresthreat detection and policy enforcementbefore encrypted traffic reaches critical internal servers.
However, itbreaks end-to-end encryptionsince the firewall acts as an intermediary.
B. It acts transparently between the client and the internal server.❌
Incorrect, because SSL Inbound Inspection requires the firewall toactively terminate and re-establish SSL connections, making it anon-transparent MITM.
C. It decrypts inbound and outbound SSH connections.❌
Incorrect, becauseSSL Inbound Inspection applies only to SSL/TLS traffic, not SSH connections. SSH decryption requires a different feature (e.g., SSH Proxy).
D. It decrypts traffic between the client and the external server.❌
Incorrect, becauseSSL Inbound Inspectionis designed to inspecttraffic destined for an internal server, not external connections.SSL Forward Proxywould be used for outbound traffic decryption.
Firewall Deployment– SSL Inbound Inspection is used inenterprise environmentsto monitor encrypted traffic heading to internal servers.
Security Policies– Decryption policies control which inbound SSL sessions are decrypted.
VPN Configurations– PFS is commonly used inIPsec VPNs, ensuring that keys change per session.
Threat Prevention– Enables deep inspection ofSSL/TLS trafficto detect malware, exploits, and data leaks.
WildFire Integration– Extracts potentially malicious files from encrypted traffic foradvanced sandboxing and malware detection.
Panorama– Providescentralized management of SSL decryption logs and security policies.
Zero Trust Architectures– Ensures encrypted traffic iscontinuously inspected, aligning withZero Trust security principles.
Firewall Behavior with PFS and SSL Inbound InspectionWhy Other Options Are Incorrect?References to Firewall Deployment and Security Features:Thus, the correct answer is:✅A. It acts as meddler-in-the-middle between the client and the internal server.
