WAF, or Web Application Firewall, is a security tool or software solution that also helps protect web applications from various types of attacks and vulnerabilities. It acts as a filter between web applications.
A WAF’s primary function is to detect and prevent malicious activities that target web applications. It accomplishes this by inspecting the content of web requests and responses for patterns or behaviours that may indicate a potential attack. When it detects a threat, the WAF can block the request, notify administrators, or modify it to remove the malicious elements.
For example, attack detection, traffic filtering, rule-based protection, application-specific protection, logging and monitoring, security policy enforcement, and rate limiting.
However, WAF is critical to protecting web applications from attacks, vulnerabilities, and data breaches. It adds an extra layer of security to the application layer, helping to protect sensitive information, maintain availability, and ensure the integrity of web applications.
On the other hand, a firewall is a broader network security device that works at the network layer. It also controls and filters traffic based on predetermined rules and policies, working at the packet level to monitor and control data that moves across networks.
Differences between a WAF and a Firewall
Functionality and Operation
Firewall
Network-Level Protection: Firewalls provide broader protection at the network layer, monitoring and controlling traffic based on network-level attributes.
Access Control: Firewalls enforce access control policies, allowing or blocking traffic based on predefined rules and restrictions.
Traffic Filtering: They examine network packets, inspecting factors like IP addresses, ports, and protocols to determine whether to permit or deny traffic.
Network Security: Firewalls concentrate on avoiding unauthorised access, minimising network threats, and ensuring the security and integrity of the network infrastructure.
WAF
Application-Level Protection: WAFs focus on the application layer, providing targeted protection to web applications against web-based attacks and vulnerabilities.
Attack Detection: WAFs employ distinct techniques like signature-based detection, behavioural analysis, and heuristics to identify patterns or behaviours indicative of web application attacks.
Web Traffic Inspection: They inspect the content of web requests and responses, analysing parameters, payloads, headers, and other application-layer data for anomalies or suspicious activities.
Web Application Security: WAFs specialise in protecting against specific web-based threats like SQL injection, cross-site scripting (XSS), cross-site request forgery (CSRF), and other application-layer vulnerabilities.
Security Focus and Deployment
Firewall
Network Infrastructure Protection: Firewalls focus on securing the entire network infrastructure, including all devices, servers, and also systems connected to the network.
Deployment: They are typically deployed at the network perimeter, acting as the first line of defence between internal networks and external networks. Firewalls are commonly placed between routers and switches.
WAF
Web Application Protection: WAFs concentrate on safeguarding specific web applications and mitigating attacks that target these applications’ vulnerabilities.
Deployment: WAFs are typically put closer to the web applications they protect. They are placed in front of web servers or integrated into the application delivery infrastructure.
Rule Sets and Customization
Firewall
Rule Sets: Firewalls use rules and policies to determine traffic allowance or blocking based on network-level criteria such as IP addresses, ports, and protocols.
Customisation: Administrators can customise firewall rules to align with the organisation’s unique safety requirements and policies.
WAF
Rule Sets: WAFs use predefined security rules and signatures to detect and block known attack patterns targeting web applications.
Customisation:
Customising WAF rules with app-specific rules can improve protection against app-specific threats.
While WAFs and firewalls contribute to a secure infrastructure, their focus and deployment are distinct. WAFs focus on protecting specific web applications against web-based attacks and vulnerabilities.
On the other hand, firewalls provide network-level protection for the entire infrastructure.
WAFs operate at the application layer, inspecting the content of web requests and responses, whereas firewalls monitor traffic at the network layer.
Deploying a firewall and a WAF can improve overall security by providing layered defence and protecting the network infrastructure and the web applications it hosts.
Moreover, Understanding the differences between WAF and firewalls is critical for organisations developing comprehensive security strategies and maintaining their assets in an ever-changing threat landscape.