AttackVector.tech

What is Firewall?

A firewall is a network security device filtering traffic based on rules. Discover types like stateful, NGFW, and WAF, and their importance.

Explain Like I'm 5

Think of your computer network as a house. A firewall is like the front door that decides who can come in and who should stay out, based on a set of rules. For example, you might let in your friends and family but keep out strangers.

There are different kinds of firewalls, similar to having different types of security systems for your house. A simple one might just check if someone is on a guest list, while a more advanced one might check what they're carrying or where they've been before letting them in. Some firewalls even watch what people do inside to ensure they aren't causing trouble.

This is important because, just like you wouldn't want burglars in your house, you don't want hackers messing with your computer network. A firewall helps keep your digital space safe by keeping out the bad guys.

Technical Definition

Definition

A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It serves as a barrier between a trusted internal network and untrusted external networks, such as the internet.

How It Works

  1. 1Packet Filtering: Examines packets transferred between computers, allowing or blocking them based on IP addresses, ports, and protocols.
  2. 2Stateful Inspection: Tracks active connections and makes decisions based on the state of network connections.
  3. 3Proxies: Act as intermediaries that fetch data on behalf of a client, adding a layer of security.
  4. 4Next-Generation Features: Incorporates intrusion prevention systems, deep packet inspection, and application-level inspection.

Key Characteristics

  • Stateful vs. Stateless: Stateful firewalls keep track of active connections, while stateless firewalls inspect packets individually.
  • Next-Generation Firewall (NGFW): Includes advanced features like application awareness and intrusion prevention.
  • Web Application Firewall (WAF): Protects web applications by filtering and monitoring HTTP traffic.
  • Host-based vs Network-based: Host-based firewalls are installed on individual devices, while network-based firewalls protect entire networks.

Comparison

Firewall TypeDescription
StatefulTracks the state of active connections.
StatelessInspects packets individually without context.
NGFWOffers features like IPS and deep packet inspection.
WAFSpecializes in protecting web applications.

Real-World Example

The CVE-2019-5786 vulnerability was a zero-day exploit in Google Chrome that required robust firewall configurations to mitigate potential attacks targeting vulnerable systems before patches were applied.

Detection & Prevention

  • Regular Updates: Keep firewall software and rule sets up-to-date to defend against new threats.
  • Testing Tools: Use tools like nmap and Burp Suite to assess firewall configurations.
  • Layered Security: Deploy alongside other security measures like intrusion detection systems for defense-in-depth.

Common Misconceptions

  • Firewalls are Impenetrable: No security measure is completely foolproof. Firewalls can be bypassed by sophisticated attacks.
  • Once Set, Forget: Firewalls require regular updates and monitoring.
  • All Firewalls are the Same: Different types of firewalls serve different purposes and offer varying levels of protection.

Keywords

what is FirewallFirewall explainedFirewall detectionFirewall typesstateful firewallnext-generation firewallweb application firewallFirewall security

Ready to scan your site?

AttackVector uses AI agents to find vulnerabilities before attackers do. Start a free scan now.

Start Free Scan