Inspection Policies (Mitigates application-layer attacks including Heartbleed)

[JaelDS]

Implementation of deep packet inspection rules that examine traffic content beyond basic header information. These policies identify and block malicious patterns associated with application vulnerabilities like Heartbleed, preventing exploitation attempts by filtering traffic based on protocol behaviors and known attack signatures at the application layer.

• Configure deep packet inspection:

policy-map global_policy
class inspection_default
inspect ftp
inspect http
inspect tls
inspect esmtp
service-policy global_policy global

• Configure SSL settings to prevent Heartbleed:

ssl encryption aes128-sha1 aes256-sha1
ssl server-version tlsv1.2
ssl client-version tlsv1.2

[JaelDS]

Inspection Policies

I will mark as done the configuration but most the security is at 80% of inspection of internet traffic. Is important to implement the SSL policies, the TLS inspection and the ESMTP inspection to have the complete solution.

TLS/SSL Inspection:

TLS inspection is crucial for a Next-Generation Firewall because encrypted traffic can hide malicious content. Without TLS inspection, encrypted connections become blind spots in your security infrastructure. Modern threats frequently use encryption to bypass traditional security controls.
A proper TLS inspection implementation would:

• Decrypt and examine encrypted traffic for threats
• Apply security policies to content regardless of encryption
• Identify and block malware, data exfiltration, or command-and-control traffic hidden in encrypted sessions
• Balance security with privacy through selective decryption policies

ESMTP Inspection:

Email remains one of the primary attack vectors for organizations. ESMTP inspection provides:

• Protection against email-based threats like malicious attachments
• Verification of protocol compliance to prevent exploitation
• Defense against command injection attacks via SMTP
• Size enforcement to prevent DoS attacks
• Protection against email address harvesting and enumeration

Production Implementation Importance

In a real production environment, these inspection capabilities would be fundamental to achieving true NGFW functionality. Without them:

• You lose visibility into encrypted traffic, which now represents 80-90% of all web traffic
• You cannot detect threats that leverage encrypted channels
• Email-based attacks might bypass your security controls
• You rely solely on IP/port filtering, similar to traditional firewalls