39 lines
1.3 KiB
Markdown
39 lines
1.3 KiB
Markdown
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## Execution/Compiliation/Verification Workers
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Submitted assignments for C/C++ but also many otehr languages need to be build
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or compiled before you can run them. Finally the submitted solutios shall be
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verified automatically to some extend.
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### Execution of Untrusted Code
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The general problem here is to provide a safe environment that jails the
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program into a sandbox leaving the rest of the system inpenetrable. This is
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considered generally NOT possible in practice as exploits can exist in any
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complex systems.
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These opportunities to exploit the system are especially given when lower levels
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are used. C code generally offers a wider range of possible attacks. Besides
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a planned attack on a system, systems may be brought down also by accident.
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* DOS of the Test Environment (CPU, RAM, Network..)
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* Fork-Bombs
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### Mitigation Measures
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* Dedicated Hardware on a seperate Network
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* Virtual Machines
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* Containers (e.g. Docker, LXC)
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* Apparmor / SE Linux
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* Limit resources (CPU, RAM, Disk, Network)
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* lower nice values to keep system responsive
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* Filesystem Privileges
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* "least privelege"
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* cgroups
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* chroot - http://www.bpfh.net/simes/computing/chroot-break.html
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* only a very reduced tool chain
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http://blog.remoteinterview.io/post/89639823776/how-we-used-docker-to-compile-and-run-untrusted
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http://hmarr.com/2013/oct/16/codecube-runnable-gists/
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