Virtualization Vulnerabilities - CompTIA Security+ SY0-701 - 2.3
Understanding Security in Cloud-Based Virtual Machines
Challenges of Managing Virtual Machines
- The rise of cloud-based infrastructures allows for the rapid creation and management of multiple virtual machines (VMs), posing unique security challenges.
- VMs can be created and destroyed frequently, complicating the maintenance of a consistent security posture across these devices.
- Each VM may have different configurations, including varying CPU capabilities, memory sizes, and storage options, which adds to the complexity of security management.
Security Best Practices for Virtual Machines
- Despite their differences from physical devices, VMs should adhere to the same security best practices as traditional operating systems like Windows or Linux.
- Specific vulnerabilities exist within virtual environments such as local privilege escalation and command injection that need to be addressed.
Risks Associated with VM Escape
- VM escape refers to an attack where an intruder gains access from one VM to another on the same hypervisor, potentially compromising multiple systems simultaneously.
- A notable instance occurred during the Pwn2Own competition in March 2017 when attackers exploited a vulnerability in Microsoft Edge's JavaScript engine leading to a successful VM escape.
Resource Management Concerns
- Hypervisors manage resources among multiple VMs but do not guarantee exclusive access; this can lead to resource reuse issues.
- For example, if a hypervisor allocates more memory than physically available (e.g., 6 GB allocated while only 4 GB exists), it risks sharing memory areas between VMs.
Implications of Resource Sharing
- Shared memory areas can create vulnerabilities if a hypervisor has bugs that allow one VM to write data that another VM can read.