A web application firewall is software that filters out malicious requests and content from your website, which protects your visitors from harm, as well as safeguards your intellectual property and the time and expense that went into developing your website.
The firewall software resides on the same server as your website. Among the common types of attacks that it can protect against are:
- SQL Injection – This refers to a technique for gaining unauthorized access to a database, such as SQL, which is used by many content management systems. With successful entry, a hacker can read sensitive information, add harmful information, or delete the entire database which would destroy your website.
- Malicious File Upload – This attack is usually applied against websites that publish user-uploaded content. If a malicious file is uploaded, such websites could be defaced or used for a phishing attack.
- Directory Traversal – This type of attack allows access to restricted directories and executes commands outside of the web server’s root directory.
The firewall can also apply a number of generic rules that use pattern matching to determine if the request looks malicious. This helps prevent 0-day attacks that are already in the wild but not yet listed in your firewall. Depending on what type of firewall you have and whether you subscribe to its update service, your firewall may update automatically as new threats emerge, providing your website with real-time protection.
Another important feature of the web application firewall is brute force protection, which blocks repeated login attempts. This capability is especially useful when your website is being hammered by automated bots. The firewall can be configured to limit unauthorized login attempts to a specific number and then lock out further attempts for as long as a few months.
If you notice too many attacks coming from specific IP addresses or countries, you can blacklist them in the firewall so they will be prevented from accessing your website. If you are concerned about the possibility of locking yourself out, you can whitelist your own IP address. This will exempt you from all the tight rules you have imposed on potential attackers.
A web application firewall offers so many more capabilities… Together, they help protect your online assets, safeguard your reputation, and maintain visitors’ confidence.
Nathan Muller is the author of 29 technical books and over 3,000 articles that have appeared in 75 publications worldwide. He also writes articles, blogs and social media content for tech companies and their executives.