Lecture Notes on Security in Cloud-Based Infrastructures

Introduction to Virtual Machines in Cloud Environments

• Cloud infrastructures enable rapid creation of multiple virtual machines (VMs).
• Security management is challenging due to the dynamic nature of VM creation and deletion.
• VMs can have varying configurations:
  • Different CPU capabilities
  • Varying memory and storage allocations

Security Concerns for Virtual Machines

• VMs run operating systems like Windows or Linux and require similar security practices as physical devices.
• Specific vulnerabilities in virtual environments:
  • Local privilege escalation
  • Command injection
  • Information disclosure

VM Escape

• Definition: Moving from one VM to another on the same hypervisor.
• Impact: Gaining access to multiple VMs and their data.
• Example: March 2017 Pwn to Own competition
  • Exploited Microsoft Edge's JavaScript engine
  • Escalated through Windows 10 kernel to VMware
  • Demonstrated bug allowed VM hopping, later patched by VMware

Resource Reuse

• Hypervisors manage resources (memory, storage, CPU) between physical and virtual worlds.
• Potential issues with resource allocation:
  • Over-allocation example with RAM: 4GB physical RAM shared among VMs totaling 6GB allocated.
  • Memory areas may be shared; problems arise if hypervisor fails in managing resource sharing.
• Solution: Update code to manage memory correctly, preventing unwanted resource sharing.