Cloud adoption and the rapid growth of remote work environments have led many businesses to take advantage of virtualized servers.
Virtual machines (VMs) offer businesses and developers a cost-effective way to consolidating their servers in a neat package. Businesses and developers can now deploy their applications or offer their products and services with immense flexibility and agility.
However, virtual servers are not as secure as was previously presumed. Just as physical servers, they require stringent security protocols and measures to avoid breaches and attacks.
2020 saw an unprecedented number of disaster scenarios such as malware, hypervisor attacks, application-layer attacks and other targeted attacks.
But how can we keep our virtual servers as secure as possible?
The Need to Protect the Hypervisor to Protect Applications
The hypervisor is anticipated to be secure and vigorous because it manages how guest OS access resources in the virtual environment and prevents intrusion across multiple resources through partitioning. However, they are also accessible to attacks. If attackers gain command of the hypervisor, they gain control of all VMs in that network and the data accessed by them. Some well-known attacks include Hyperjacking and Bluepill, which inserts VM-based rootkits to install rogue hypervisor or alter the existing one. Since hypervisors run underneath the host OS, we need a separate security measure for it.
However, we categorize, Cloud-based attacks on virtualized systems are broadly categorized as hypervisor-based, VM-based and VM-image.
So we must implement robust security measures targeted at each of these categories to protect our virtual servers.
Of course, there is no comprehensive knowledge of the security measures required, as hacking activities constantly evolve. Nonetheless, here are helpful tips and hacks for protecting virtual servers.
1. Update Containers and Virtual Machines
Different organizations have different scopes and requirements in their workloads, determining how they use virtualization technologies to fulfill their needs. For instances, enterprise and developers use virtual machines because they require flexibility in running multiple applications. In contrast, organizations seeking scalability use containers.
However, both VMs and containers offer opportunities to run applications multiple times or isolate them on single platforms.
The difference is their approach. Virtual machines virtualize hardware to run instances of the operating system. In contrast, containers virtualize an operating system to run various workloads in the same OS instance.
No matter our choice, every instance of applications running on virtual machines and containers pose a significant risk if misconfigured or vulnerable. It is vital to implement new updates as soon as they arrive.
2. Implement Patches and Use Only Virtual-Machine Oriented Hardware
Implementation does not stop at installation; we must apply all security patches suggested by the OS provider. Updating performance without the patches carries enormous risk.
Updates usually include patches to address security flaws, including what we may not have been aware of. Installing the updates without the patches means the flaws might continue to reside on our virtual servers. It increases the possibilities of attacks that we cannot hold the OS provider responsible. So we must patch and update containers and VMs as regularly as possible.
Overall, it is also important to use hardware specifically designed for virtual machine usage. Trying to manage outdated hardware can become a recipe for disaster.
3. Remove Unused and Unnecessary Applications
Never download and leave apps running when they are unnecessary and not in use. Such action is a surefire way to allow hackers access to our systems. Deleting and disabling such unnecessary and unused virtual hardware, ports, and service can help minimize attack surfaces.
Furthermore, we need to continuously monitor apps running on the virtual server, who added those apps, and the activities within the applications. The less software we have running on the virtual server, the lower the possibilities of an attack via our applications.
4. Use Templates and Scripted Management
Using templates or scripted management helps reduce risks of misconfiguration when installing guest operating systems and applications on a virtual machine. Therefore, virtual machine templates help us configure guest operating systems and other virtual machines according to pre-set requirements. Even when we want to change the virtual machine settings after initial deployment, it is easy to optimize those scripts and keep the virtual environment consistent.
5. Virtual isolation
If virtual machines do not need to communicate with one another, consider isolating and using separate network cards for the different network ranges. No doubt, virtual isolation also introduces its additional risk, but this can be manageable.
It’s also essential to track and restrict the creations of virtual services and VMs to prevent virtualization sprawl. Virtualization sprawl is a scenario where there are too many instances running, leading to inefficient physical and virtual resources management.
6. Have a Disaster Recovery Plan
Regular server snapshots and data backups offer opportunities to reset systems in time should attacks occur. It makes it easier to identify security gaps and fix them accordingly. This is off-course for the worst-case scenario, but backing up data and authenticating server snapshots can efficiently minimize downtime and recovery.
7. Active Monitoring of Traffic between VMs with Explicit Visibility
Dramatically decreased running speed or spikes in traffic might be a sign of a denial of service (DOS) attack is occurring. This can be a problem for companies requiring continuous uptime. DOS and distributed denial of service (DDoS) attack commonly prevent and disable virtual machines and networks from functioning correctly.
Regardless, constant monitoring is instrumental to early detection to help stop and remediate DOS and DDOS attacks before they become too large. By staying on top of all the happenings in the virtual environment, we can stop and prevent other attacks before they cause undue damage.