application security using a copy-on-write virtual machine

An architecture is possible that uses a lightweight VM for use as an application sandbox. Instead of the duplication of an OS plus a run-time environment, this virtual machine uses the host environment as a read-only resource. This allows the VM to serve as a Sandbox that allows reads and writes to the file system, but only the VM address space is modified. Since the host OS environment is supplying a-prior values, the total VM footprint is minimal. This architecture is able to serve as a base for secure application solutions.

In practice an application is installed into a host OS and via installation and use it creates a cache mirror of changed OS data and resources that it would normally have modified in the traditional installation. This application and the ‘cache’ is then versioned and mirrored. If the application is compromised it is deleted or the cache is rolled back to the period before the compromise.

There are many types of virtual machines. Two examples are the system VM types such as VMWare or Oracle VirtualBox, another is the focused process VM such as the Java Virtual Machine, Dalvik VM, or the Common Language Runtime. The former are complex and since they must “dupe” an OS are large and complex. The latter application level VMs are smaller and optimized for a single runtime environment. Each of these have corresponding security issues.

A virtual machine is usually a sandbox in implementation and provides a level of security. However, the cost is that it must duplicate OS resources. In contrast the sandboxed process VM type being discussed here depends on a real OS host and does as little duplication of the environment as possible. It is not generic, but integral to a specific application program or system.

Though this may possibly help in making an application survive destruction by protecting the storage address space, there is still the issue of active infiltration and use of system resources such as networks accessible to the application. Perhaps this type of VM will make conventional security practices and tools more useful?

Summary
Just an idea off the top of my head. Haven’t looked to see if is unique or even remotely makes sense.

Updates
June 12, 2013: “Security Anti-Pattern – Mobile Hypervisors (for user facing VM’s)”
August 31, 2013: Was just reading about Docker which uses the LXC (LinuX Containers). Maybe that is what I had in mind.

Further reading

1. Android Application Sandbox
2. Virtual Machine
3. Sandbox
4. “Pushing The Limits of Web Browsers … or Why Speed Matters“
5. Sandboxing Java Code
6. “Security Anti-Pattern – Mobile Hypervisors (for user facing VM’s)“

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