I would infer that it's insecure, since if it were that easy there wouldn't be various abandoned projects trying to sandbox Python.
It's the curse of any sufficiently useful language. Well, maybe not Lua, but that was specifically designed for embedding. Java also began with that intention back when applets were ahead of their time, though IIRC secure sandboxing is no longer really a feature.
I'm interested in an answer. Is there a way, by design, to run code from an untrusted source in a restricted manner? So the worse the code could do is call me rude names.
Not staying in Python. Python's run-time is not built for sandboxing.
If you set up a new runtime environment, like a FreeBSD jail, with no access to anything and a short CPU limit, then start you could start a Python subprocess in that environment, where the only thing that gets out is data via a pipe to call you names.
An operating system like FreeBSD is built to run code in a restricted manner.
I'm talking about the history beyond why rexec and Bastion, and restricted execution, were removed from Python in the 2.x days. See https://python.readthedocs.io/en/v2.7.2/library/restricted.h... , "In Python 2.3 these modules have been disabled due to various known and not readily fixable security holes."
They started because back in the 1.x days there was a Python web browser called Grail, and the hope was to support restricted Python applets in Grail.
Or from 10 years ago, read https://lwn.net/Articles/574215/ about the failure of 'pysandbox' where one of the ways to break out was to "[use] a traceback object to unwind the stack frame to one in the trusted namespace, then use the f_globals attribute to retrieve a global object." ... "Stinner's tale should serve as a cautionary one to anyone considering a CPython-based solution".
You might consider RestrictedPython at https://restrictedpython.readthedocs.io/en/latest/ which supports only a subset of Python, via AST-walking to limit what the code can do. I have no experience with it.
It's the curse of any sufficiently useful language. Well, maybe not Lua, but that was specifically designed for embedding. Java also began with that intention back when applets were ahead of their time, though IIRC secure sandboxing is no longer really a feature.
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