How to secure your internal network

Why should I restrict access to my internal network?

While external network security measures like firewalls are essential for safeguarding against external threats, internal network security is equally critical for protecting an organization's core infrastructure.

Think of your internal security as your network perimeter's last line of defense. A firewall at the edge of your network acts as the initial barrier against malicious actors attempting to infiltrate your systems. It filters incoming and outgoing traffic based on predefined security rules, effectively flagging and blocking cyberattacks that violate them.

However, with the rise of sophisticated cyber threats, traditional firewalls may occasionally fail to detect and thwart advanced attacks. This underscores the importance of implementing robust internal security measures to complement external defenses and fortify your network against evolving cyber threats.

By restricting access to your internal network, you establish additional layers of protection that help mitigate the risks associated with breaches and unauthorized access. This safeguards the integrity and confidentiality of your organization's sensitive data and resources.

How do I secure my internal network?

My development applications are restricted to employees

Our Recommendation: Restricting access to development applications ensures that only authorized employees with proper permissions can access sensitive development environments.

Risks addressed by the recommendation: This safeguards the integrity of your development process and protects against potential insider threats and unauthorized modifications.

Given that development environments may be less mature and potentially more vulnerable to exploitation, it's crucial to restrict access and ensure robust security measures are in place.

My internal applications are authenticated via SSO

Our Recommendation: Implement Single Sign-On (SSO) for internal applications. This will allow users to securely access multiple applications with a single set of credentials, simplifying the authentication process while strengthening identity and access management practices.

Risks addressed by the recommendation: By implementing SSO, even if an attacker gains access to the internal network, they cannot use your internal applications. The risk of password-related security incidents such as password reuse, phishing attacks, and credential theft is significantly reduced.

My internal/private assets are accessible only via a secure solution

Our Recommendation: Implement a VPN or bastion host to provide secure remote access to internal resources.

Risks addressed by the recommendation: By restricting access to internal assets through secure channels, the recommendation mitigates the risk of unauthorized access and potential breaches of sensitive information: even if an attacker gains access to the internal network, they cannot use your internal applications.

I have limited internal flows and have a flow matrix

Our Recommendation: Adhering to the principle of least privilege in network flows is crucial: you should only authorize inbound and outbound network flows that are necessary between the resources of your infrastructure. To achieve this, you can use network security groups on cloud providers.

For example, if a database is only accessed by an application, the database should only accept inbound network flows originating from the application. You should maintain a flow matrix to document your network traffic.

Risks addressed by the recommendation: By filtering network traffic and maintaining a flow matrix, the recommendation mitigates the risk of unauthorized access, data exfiltration, and malicious activities within the internal network.

My environments are isolated

Our Recommendation: We recommend isolating your development, testing, staging, and production environments, among others. You should isolate them to separate access to these different environments. On AWS, one account per environment. On GCP, one project per environment.

Risks addressed by the recommendation: Isolating environments ensures that illegitimate access to one environment does not compromise all of them, reducing the attack surface.

Conclusion

In conclusion, implementing network restrictions and adhering to best practices for internal network security is essential for protecting your organization's assets, ensuring compliance, and mitigating the risk of security incidents.

By following these recommendations, you can strengthen the security posture of your internal network and safeguard against potential threats and vulnerabilities.