Certified: The Security+ Prepcast

In this episode, we are focusing on two increasingly critical categories of vulnerabilities: those found in virtualization environments and those unique to cloud computing. These technologies offer flexibility, scalability, and cost efficiency, but they also introduce new risks that must be understood and managed. Misconfigurations, improper access controls, and architectural flaws can all lead to serious security incidents in both virtual and cloud systems.
Let’s begin with virtualization vulnerabilities. Virtualization allows multiple virtual machines to run on a single physical system, sharing resources like CPU, memory, and storage. Each virtual machine is supposed to be isolated from the others, but certain vulnerabilities can break that isolation.
One of the most serious threats is virtual machine escape. This occurs when an attacker inside a virtual machine is able to break out of that environment and gain control of the host system or other virtual machines on the same host. A successful virtual machine escape means that the attacker now has access to the hypervisor layer—the software that manages all virtual machines on the host.
These attacks are rare but extremely dangerous. They usually exploit flaws in the hypervisor or drivers used by the host system. In some cases, a vulnerable guest operating system may be used to run code that targets the hypervisor directly. If successful, the attacker can access sensitive data, install backdoors, or shut down other virtual machines.
Another virtualization risk involves resource reuse. This refers to the reuse of memory, disk space, or other shared resources between virtual machines. If the hypervisor does not securely wipe these resources before they are reassigned, data from one virtual machine could be accessed by another. This can lead to unauthorized data exposure, especially in environments with multiple tenants or users.
To mitigate virtualization risks, administrators should keep hypervisors and guest systems fully patched, disable unused features, and enforce strict access controls on the management interface. Virtual machines should be segmented by function or sensitivity level, and logging should be enabled to monitor for abnormal behavior. Secure configuration baselines for each virtual environment can help reduce the risk of missteps that open the door to escape or resource leaks.
Now let’s turn to cloud-specific vulnerabilities. Cloud computing environments are built to deliver services over the internet, including infrastructure, platforms, and applications. But the very flexibility that makes cloud so appealing can also create significant security gaps—especially when users and administrators don’t fully understand their responsibilities in a shared environment.
One of the most common cloud vulnerabilities is misconfigured cloud storage. Cloud providers offer powerful storage services, but if permissions are left open or settings are incorrect, sensitive data may be publicly exposed. There have been many incidents where company files, customer information, or internal documents were accessible to anyone who had the link. These misconfigurations are not typically caused by flaws in the cloud platform, but by mistakes made during setup.
Another significant cloud risk involves identity and access management. Cloud environments often rely on a combination of user accounts, access tokens, and API keys to manage permissions. If these credentials are too broad, improperly stored, or not rotated regularly, they can be exploited by attackers to move laterally, escalate privileges, or exfiltrate data.
A common scenario involves an employee uploading code to a public repository without realizing it contains cloud access keys. Once discovered by attackers, those keys are used to take over cloud resources, create new users, or spin up virtual machines for mining cryptocurrency—all at the expense of the organization.
To secure cloud environments, organizations should follow best practices that include enforcing the principle of least privilege, using multi-factor authentication, and regularly auditing access controls. Cloud providers offer built-in tools to review configurations, monitor traffic, and alert administrators when something looks unusual. These tools should be used continuously—not just during initial setup.
Data encryption is another important layer of defense. Data should be encrypted both at rest and in transit, and encryption keys should be managed through a centralized and secure key management system. Cloud workloads should be designed with segmentation and failover in mind to limit the impact of a breach and maintain availability.
Finally, it's important to understand the shared responsibility model. In cloud computing, the cloud provider is responsible for securing the underlying infrastructure, while the customer is responsible for securing everything they deploy on top of it. This includes access controls, data, application settings, and network configurations. Misunderstanding this division of responsibility is a leading cause of cloud-related breaches.
As you prepare for the Security Plus exam, make sure you understand the differences between virtualization vulnerabilities like virtual machine escape and resource reuse, and cloud-specific issues like storage misconfigurations and identity management failures. You may be asked to identify which environment is being exploited in a given scenario, or which defense would best reduce the risk of a particular flaw. Watch for clues that reference hypervisors, virtual machines, cloud storage buckets, or access keys—these details can help you choose the correct answer.