Cloud-Based Infrastructures and Virtual Machines

Introduction

• Cloud infrastructures allow for rapid and simultaneous creation of virtual machines (VMs).
• Managing VMs has unique security challenges compared to physical devices.

Security Concerns in Virtual Machines

• Frequent Changes: VMs are created and destroyed frequently, complicating security management.
• Configuration Variability: VMs can differ in CPU count, memory, storage, and operational capabilities.
• Similarities to Physical Devices: Despite differences, VMs run operating systems (OS) like Windows or Linux, requiring similar security measures.

Specific Vulnerabilities in Virtual Environments

• Common vulnerabilities: local privilege escalation, command injection, information disclosure.
• VM Isolation: VMs operate independently with their own resources and should not interfere with each other.

VM Escape

• Definition: Occurs when an attacker moves from one VM to another on the same hypervisor.
• Example Incident:
  • At the Pwn2Own competition in March 2017, a VM escape was demonstrated using a bug in Microsoft's Edge browser and Windows 10 kernel.
  • Exploited a VMware bug to move between VMs on the same hypervisor.
• Resolution: VMware patched the vulnerability promptly.

Resource Reuse Concerns

• Hypervisor Role: Manages allocation of physical resources (memory, storage, CPU) to VMs.
• Resource Allocation Issue:
  • Example: 4GB RAM allocated to a host, 3 VMs each assigned 2GB, exceeding physical capabilities.
  • Hypervisors manage resource allocation dynamically, but bugs can cause resources to be improperly shared.
• Security Risk: Improper management can lead to data leakage between VMs.
• Solution: Update hypervisor code to prevent sharing errors and ensure resource isolation.

Conclusion

• Understanding and mitigating security risks in virtual environments is crucial.
• Continuous updates and monitoring are essential to safeguard cloud-based infrastructures.