Web Application Firewall (WAF) shields web applications from attacks like cookie poisoning, SQL injection, and cross-site scripting (XSS). Some of these known attacks are addressed by a negative security model known as Blocklist WAFs. And on the other hand, Allowlist WAFs take in previously approved traffic. In reality, they both work together in a hybrid system.
How Does WAF Work?
When it comes to how WAF services function, it’s best to say that they filter outgoing and incoming traffic. As a protocol layer seven defence, a WAF operates through a group of guiding principles referred to as policies.
The speed of policy change determines the rate of adaptation to different types of attacks. Such speeds differ from one WAF to another and are a quality indicator of WAFs. Unlike a proxy server that shields client identity, a WAF insulates web application servers from bad clients.
Types of Web Application Firewalls
Web Application Firewalls (WAFs) come in different ways. There are the Network-based, Cloud-based and Host-based WAFs.
These are physical equipment that is installed and maintained at a physical location. Although Network-based WAFs are costly, they cut down on latency.
These are a much cheaper and easier option to use. Users get to pay a small fee monthly or annually for the service of security. Some would say that a setback for this option is the lack of control. But its flexibility in adapting to new attacks via seamless updates can be worth it.
This WAF option is less costly than the Network-based WAFs but costlier than Cloud-based WAFs. They’re part of app software and can be extensive, skill, money and time-wise when it comes to maintenance.
How To Use Web Application Firewalls
Web Application Firewalls (WAFs) can be used in many ways. You have the following below.
- On-premises Advanced WAF;
- Cloud-based + Auto-Provisioned;
- Cloud-based + Fully Managed Security As A Service;
- Cloud-based + Self Managed.
On-premises Advanced WAF
These can be the best option for high-demand environments where security, performance and flexibility have real and unavoidable consequences. They can be hardware or virtual.
Cloud-based + Auto-Provisioned
Auto-Provisioned takes control but offers peace of mind as the Cloud-based WAF
implements security guidelines simply and efficiently.
Cloud-based + Fully Managed As A Service
Fully-Managed-As-A-Service is the best option if you like speed and are resource-constrained regarding IT and security equipment and staff. You can still get WAF for your applications using this option.
Cloud-based + Self Managed
With the Self Managed WAF, you trade a little bit of simplicity for control and context of traffic flow and security guidelines. Flexibility is a core feature here.
WAFs vs IPS vs NGfW
A Web Application Firewall (WAF) sits between web applications and their users, analysing all interactions between them. They filter out actions that aren’t based on security policies and are usually the first defence shield used by companies for their applications.
Of the three security products mentioned in this segment, WAFs work at the application level or layer 7. And its guidelines are focused on the OWASP Top 10.
Next-generation Firewall (NGFW) screens traffic going into the web. This is fine across Software-as-a-Service (SaaS), websites and more. And it involves implementing user-based guidelines and adding its own Intrusion Prevention Systems (IPS) and URL filtering. Unlike WAF, which is a reverse proxy, the NGFW is a forward proxy.
Intrusion Prevention Systems (IPS) is a broad security product that usually protects layers 3 and 4 of the network and session layers of protocols such as TELNET, SSH, DNS, SMTP and FTP. A few could offer some security at the application level. It uses signature databases and established policies.
If you keep any questions, you can leave a comment, and we’ll be happy to answer them.