Just wondering if anyone has expertise on how to securely run code uploaded or typed in by users. I am curious about how those online coding environments are able to work securely without the worry of the server environment being attacked.
A thought I had was using Docker as a means to run the code.
Thanks!
https://blog.golang.org/playground
NodeJS also includes a sandbox in its standard lib. And there are more advanced versions out there:
https://github.com/patriksimek/vm2
Good luck and be careful ;)
On freebsd, you'd use something like capsicum. On linux, something like seccomp. Although, nowadays I imagine people would think of just running in a VM or a container.
1. Run your users code outside of your secured network. If you have a network with a VPC, make sure you're not running users code within your VPC.
2. Restrict network access. If the code doesn't need to talk with the outside world, don't allow egress traffic.
1. Accessing and exploiting system resources like file system, network stack etc. Generally this can be mitigated by providing a method to whitelist api calls. Jvm security manager has this capability.
2. Exhaust memory by abusing heap allocation. Some os have the capability to limit memory usage per process. Some language run times can like jvm maxheap flag. Note this is per process, not per user request/script.
3. Hog the cpu, starving other process/requests/scripts. Again there are os level abilities to limit cpu per process, again not for individual request/script.
I don’t know of any language/runtime that covers these three areas, if you do, or if I missed anything, please share!
Sandbox will in all probability be running alongside application code so the risk is an attacker gaining complete covert control!