What is a Web Application Firewall (WAF)?A Web Application Firewall (WAF) helps protect web applications by filtering and monitoring HTTP traffic between a web application and the Internet traffic and by blocking bad HTTP traffic, malicious web service requests, and automated botnets attack.
A WAF can be considered a reverse proxy protecting the servers from exposure by having clients pass through the WAF before reaching the server.WAFs are especially useful to companies that provide products or services over the Internet, such as e-commerce shopping, online banking, and other interactions between customers or business partners.
GET requests are used to retrieve data from the server, and POST requests are used to send data to a server to change its state.A Web Application Firewall is generally configured according to three basic security approach:Whitelisting approach: It allows only pre-approved traffic that meets specifically configured criteria.
This approach is best suited for use on internal networks that are used only by a limited group of users (for instance, employees).
This security approach is best suited for web applications on the public internet as legitimate requests can come from unfamiliar client machines.
WAFs have standards rules embedded in it, but your server administrator can adjust these and add on custom rules as well.Common Web Application Security Risks:Injection attacksBroken AuthenticationSensitive data exposureXML External Entities (XXE)Broken Access controlSecurity misconfigurationsCross Site Scripting (XSS)Insecure DeserializationUsing Components with Known VulnerabilitiesInsufficient Logging & MonitoringWhat Attacks do WAFs protect against?