How to Fix Security Warnings

Common Fixes for Lynis Warnings

1. Kernel Hardening

sudo nano /etc/sysctl.conf

Add:

net.ipv4.tcp_syncookies = 1
net.ipv4.ip_forward = 0

2. Enable Firewall

sudo ufw enable

3. Secure Shared Memory

sudo nano /etc/fstab

Add:

tmpfs /run/shm tmpfs defaults,noexec,nosuid 0 0

4. Run Lynis Again to Verify

sudo lynis audit system