Introduction
You can patch your apps, scan your code, and still be exposed — if your system isn’t properly hardened. But what does hardening actually mean?
Let’s take a closer look.
1. What is Hardening?
Hardening is the process of securing a system by reducing its attack surface. That means:
- Removing unnecessary components
- Disabling unused services
- Locking down default configurations
The goal is to minimize the ways an attacker can get in.
2. What can you harden?
Hardening applies to everything in your infrastructure:
- Operating systems (Linux, Windows)
- Containers & images
- Network configurations
- Cloud environments
- CI/CD pipelines
- Applications & APIs
Each layer has its own set of best practices.
3. Examples of Hardening
- Disable root login over SSH
- Close unused ports and services
- Remove default credentials
- Apply strict file permissions
- Limit installed packages
- Use minimal base images for containers
- Enable audit logs and monitoring
4. Hardening Standards and Benchmarks
To help guide the process, there are official security benchmarks such as:
- CIS Benchmarks (Center for Internet Security)
- DISA STIGs (U.S. DoD)
- NIST SP 800-53 (U.S. cybersecurity framework)
Tools like Lynis, OpenSCAP, or CIS-CAT can scan systems against these benchmarks.
5. Why Hardening Matters in DevSecOps
- Prevents default misconfigurations from becoming vulnerabilities
- Improves baseline security posture
- Helps with compliance (e.g. ISO 27001, SOC 2)
- Reduces noise for security monitoring tools
In short, it’s a foundational practice for building secure-by-default systems.
Conclusion
Hardening means locking down your systems to reduce risk — stripping away anything that isn’t needed, and securing what is. It’s one of the simplest, most powerful ways to defend against attacks.
That’s what hardening is.