How to Install ModSecurity for Apache

Step 1: Install ModSecurity

sudo apt install libapache2-mod-security2 -y

Step 2: Enable Module

sudo a2enmod security2
sudo systemctl restart apache2

Step 3: Configure Core Rules

sudo cp /etc/modsecurity/modsecurity.conf-recommended /etc/modsecurity/modsecurity.conf
sudo nano /etc/modsecurity/modsecurity.conf

Change:

SecRuleEngine On

Step 4: Install OWASP CRS

sudo git clone https://github.com/coreruleset/coreruleset /usr/local/coreruleset
sudo cp /usr/local/coreruleset/crs-setup.conf.example /usr/local/coreruleset/crs-setup.conf

Step 5: Include in Apache Config

sudo nano /etc/apache2/conf-available/security2.conf

Add:

Include /usr/local/coreruleset/crs-setup.conf
Include /usr/local/coreruleset/rules/*.conf

Step 6: Restart Apache

sudo systemctl restart apache2