Why does private cloud need its own security best practices?
A private cloud isolates your workloads down to the hardware level, which removes the risk of other customers’ workloads sharing your physical infrastructure. It also gives you control over your security architecture, so measures and practices can be tailored to your requirements, which is why it suits organisations with strict compliance needs, such as those in financial services, the public sector and healthcare.
Isolation is a strong foundation, but it does not secure an environment by itself. Attacks can happen whatever the setup, and most begin with something ordinary, such as stolen credentials, an unpatched system or an exposed management interface. These best practices focus on closing those routes.
How is security shared between you and your provider?
Security in a private cloud is a shared responsibility. The provider is typically responsible for the hardware, datacentre and platform, while you remain responsible for your data, who can access it and how your applications are configured. In a managed service, the provider can also take on tasks such as patching, monitoring and firewall management, but the split should always be agreed in writing.
The UK’s National Cyber Security Centre (NCSC) publishes 14 cloud security principles to help you choose a provider that meets your security needs. They cover areas such as data in transit, separation between users, operational security, supply chain security, identity and authentication, and secure use of the service, and they are a useful checklist whichever provider you consider.
What are the best practices for securing a private cloud?
Control identity and access
Use multi-factor authentication (MFA) on all systems, particularly administrator accounts, remote access and email. Apply the principle of least privilege, using role-based access controls so that people and systems have only the access they need, and review accounts regularly. Retire credentials that were issued for projects or pilots and are no longer needed, and verify requests to reset access before acting on them.
Protect the management plane and hypervisor
The management layer controls every virtual machine on a host, so it is a high-value target, and attackers are increasingly shifting their focus to the hypervisor layer. Keep management interfaces off the public internet, segregate the management network from production and general user networks, limit access to specific administrators and devices, and prioritise patches for hypervisor vulnerabilities.
Segment your network
Separate production, development and test environments, and restrict which systems can communicate with each other. Segmentation limits how far an attacker can move if one system is compromised. Use VPNs for remote access, and firewall rules that allow only the traffic you need.
Encrypt data in transit and at rest
Protect data as it moves between networks and between components using encryption, such as current versions of Transport Layer Security (TLS) , and encrypt data at rest, including backups. Manage encryption keys carefully, and limit who can access them.
Patch and harden
Apply security updates to operating systems, the platform and applications regularly, and prioritise internet-facing systems and management components, where a flaw has the greatest impact. Remove services you do not need, and build new systems from a hardened baseline configuration.
Monitor, log and respond
Continuous monitoring, log analysis and intrusion detection and prevention help identify suspicious activity before it becomes an incident. Keep audit logs away from the systems they record, so an attacker cannot easily erase them, and review who has accessed your environment. Have an incident response plan that people have practised, covering identification, containment, communication, recovery and review. Our insight on cyber security essentials covers how to build one.
Keep independent, tested backups
Backups are what allow you to recover if prevention fails. Follow the 3-2-1 rule of three copies, on two types of media, with one stored offsite or offline, and consider immutable backups that cannot be changed or deleted. Without good backups, hypervisor-level ransomware can leave you with no way to recover. Keep backups isolated from the platform they protect, encrypt them and test restores regularly.
Protect the perimeter
Managed firewalls, a web application firewall (WAF) and Distributed Denial of Service (DDoS) protection filter malicious traffic before it reaches your workloads. Allow inbound traffic only where it is needed, and review the rules as your environment changes.
What do private cloud security myths get wrong?
Several misconceptions persist about private cloud security.
Myth: dedicated hardware means security is taken care of
Dedicated hardware provides isolation, but security still depends on configuration, patching, access controls and monitoring. Treat isolation as a foundation to build on.
Myth: private cloud is more prone to attack than on-premise infrastructure
Cyber attacks can happen regardless of setup, and being physically closer to your users does not make infrastructure safer. Maintaining strong security on-premise takes staff to monitor systems continuously and to patch servers promptly, as well as physical security. With a private cloud provider, patching, monitoring and physical security can be handled by specialists, which can lower the burden on your own team.
Myth: private cloud security limits flexibility
On-premise upgrades and innovation involve buying and installing hardware, which takes time. A private cloud can be configured to your requirements, and security features and updates can be rolled out through the platform.
Myth: private cloud security is hard and expensive
Running your own security can be demanding, but a managed private cloud shares that effort with a provider whose engineers monitor and maintain the environment, so your team can concentrate on your applications.
What should you look for in a provider’s security?
Questions worth asking include:
- Which certifications do you hold, such as ISO 27001, and are they externally audited and current?
- How do you meet the NCSC cloud security principles?
- Is data encrypted at rest and in transit, and how are keys managed?
- Which access controls apply, and who at the provider can access my environment?
- How is the platform patched, and how quickly are critical vulnerabilities addressed?
- What monitoring, intrusion detection and incident response do you provide, and is it available 24/7/365?
- How are backups protected, and how are restores tested?
- Where is my data stored, and who is responsible for each part of security?
How can a managed provider help?
A managed private cloud lets specialists take on much of this work. Our security services are layered, and can include managed firewalls, a web application firewall, DDoS defence, intrusion detection and prevention, and ransomware protection combining network security, patch management, endpoint protection, identity verification and data backup, with 24/7/365 monitoring, log analysis and threat detection. Our engineers work with you to agree what is covered, so responsibilities are clear.
The next steps
Private cloud gives you a strong base for security, through isolation and control, and good practice builds on it with strong identity management, a protected management plane, prompt patching, continuous monitoring and tested backups. Which measures matter most depends on your workloads, compliance requirements and the resources you have in-house.
If you are reviewing your security approach, speaking with an experienced managed hosting provider can help. Speak to one of our Cloud Consultants about your requirements, or explore our Managed Private Cloud and Security Services.
