A web application firewall (or WAF) filters, monitors, and blocks HTTP traffic to and from a web application. By inspecting HTTP traffic, it can prevent attacks stemming from web application security flaws. It can be used to detect SQL injection, Cross-Site Scripting (XSS), Remote File Inclusion, Security Misconfigurations, and much more.
GitLab provides a WAF out of the box after Ingress is deployed. All you need to do is deploy your application along with a service and Ingress resource. In the GitLab Ingress deployment, the ModSecurity module is loaded into Ingress-NGINX by default and monitors the traffic to the applications which have an Ingress. The ModSecurity module runs with the OWASP Core Rule Set (CRS) by default. The OWASP CRS detects and logs a wide range of common attacks.
By default, the WAF is deployed in Detection-only mode and only logs attack attempts.
The Web Application Firewall requires:
To enable the WAF, you need:
Configured Kubernetes objects
To use the WAF on an application, you need to deploy the following Kubernetes resources:
If you are using GitLab.com, see the quick start guide for how to use the WAF with GitLab.com and a Kubernetes cluster on Google Kubernetes Engine (GKE).
If you are using a self-managed instance of GitLab, you must configure the Google OAuth2 OmniAuth Provider before you can configure a cluster on GKE. Once this is set up, you can follow the steps on the quick start guide to get started.
A network firewall or packet filter looks at traffic at the Network (L3) and Transport (L4) layers of the OSI Model, and denies packets from entry based on a set of rules regarding the network in general.
A Web Application Firewall operates at the Application (L7) layer of the OSI Model and can examine all the packets traveling to and from a specific application. A WAF can set more advanced rules around threat detection.
ModSecurity is enabled with the OWASP Core Rule Set (CRS) by default. The OWASP CRS logs attempts to the following attacks:
- SQL Injection
- Cross-Site Scripting
- Local File Inclusion
- Remote File Inclusion
- Code Injection
- Session Fixation
- Scanner Detection
- Metadata/Error Leakages
It is good to have a basic knowledge of the following:
You can find more information on the product direction of the WAF in Category Direction - Web Application Firewall.