Virtual machine (VM) security is essential for maintaining the integrity and confidentiality of systems in virtualized environments. It ensures that virtual machines, which run multiple operating systems on shared hardware, remain secure and isolated.
VM security focuses primarily on the traditional system VM model, where the Virtual Machine Monitor (VMM) manages access to hardware.
(a) Virtual security services provided by the VMM. (b) A dedicated security VM
1. Role of the VMM:
The VMM acts as a mediator between the hardware and guest virtual machines. It ensures:
- Strict isolation between virtual machines.
- Controls critical operations like memory, disk, and network access.
2. Trusted Computing Base (TCB):
- Essential for VM security.
- If compromised, the security of the entire system is at risk.
3. Capabilities of VMM:
- Monitors and manages guest VMs.
- Enables, State management (Save, restore, clone, and encrypt the state of a guest VM), Cloning, Inter-VM communication.
4. VMM-based Threats:
- Resource Starvation & Denial of Service (DoS): Rogue or misconfigured VMs can exhaust (consume all) resources.
- Side-Channel Attacks: Exploiting shared resources like networks or memory due to insufficient isolation.
- Buffer Overflow Attacks: Overrunning buffer memory to execute malicious code.
5. VM-based Threats: These threats focus on individual virtual machines
- Rogue VMs: Unauthorized or insecure VMs due to weak access controls.
- Tampered VM Images: Insecure or modified VM images due to lack of verification.