Traditional firewalls and other security options may be ideal for providing general security at a network-level, however when it comes to vulnerabilities specific to web applications, like SQL injections and cross-site scripting, they just don't have the specific abilities to handle it.
A Web Application Firewall (WAF) is a specific and specialised tool that sits on the outer edge of the network, working as a defensive layer between the public side of a web application and the incoming traffic. Because a WAF protects only web applications, rather than an entire network, many people decide that it's not worth the investment - however, the fact that it only has one job to focus on is exactly why it's so effective.
A WAF can monitor, filter and block web traffic to or from a business' web applications. They are able to differentiate fraudulent interactions from legitimate traffic by analysing every single HTTP request before it reaches the application, but, to a traditional firewall, these appear genuine.
Here are 5 ways that a WAF can help to protect your web applications and data:
- Tests & encrypts URLs
When monitoring inbound traffic, WAFS will search for any suspicious URLs; this can include unexpected variables or the presence of SQL, which could indicate a future attack. For outbound URLs, many WAFs will encrypt links before they are sent to clients, protecting the original URL or directory structure from being seen by anyone but the intended recipient.
- Filters out spam traffic
WAFs will search for keywords within inbound traffic common with spam, using set rules to further distinguish this from legitimate content before the user is notified or redirected away from the application.
- Blocks DDoS attacks
In a Distributed Denial of Service attack, the target application is overloaded with a flood of fake traffic from many different sources. A WAF can prevent this by limiting the amount of requests that an IP can make for a web application, blocking traffic before it reaches the point of excess.
- Stops SQL Injections and XSS attacks
SQL Injections and Cross-Site Scripting (XSS) are the most common attacks on web applications, but a WAF can check for the presence of codes commonly used in these attacks according to preset parameters, blocking the attack before it can take effect.
- Application learning
WAFs can build positive security profiles for applications by sampling web traffic from already trusted hosts. This allows admins to enforce 'whitelist' rules on sensitive parts of the application, reducing the risk of attacks and zero-day vulnerabilities.
For more information about Altinet's WAF-as-a-Service solution:
|How the WAF secures your mobile and IOT services||Securing Web Applications against malicious file injections|