Untrusted code execution

[Rustom Mody]

On Tuesday, April 5, 2016 at 7:19:39 PM UTC+5:30, Jon Ribbens wrote:
> On 2016-04-03, Jon Ribbens wrote:
> > I'd just like to say up front that this is more of a thought experiment
> > than anything else, I don't have any plans to use this idea on any
> > genuinely untrusted code. Apart from anything else, there's the
> > denial-of-service issue.
> >
> > That said, is there any way that the following Python 3.4 code could
> > result in a arbitrary code execution security hole?
> >
> >     tree = compile(untrusted_code, "<script>", "eval", ast.PyCF_ONLY_AST)
> >     for node in ast.walk(tree):
> >         if (isinstance(node, ast.Name) and node.id.startswith("_") or
> >             isinstance(node, ast.Attribute) and node.attr.startswith("_")):
> >                 raise ValueError("Access to private values is not allowed.")
> >     namespace = {"__builtins__": {"int": int, "str": str, "len": len}}
> >     print(eval(compile(tree, "<script>", "eval"), namespace))
> 
> Nobody has any thoughts on this at all?

i actually did...

But dont know enough of the AST API to figure out what you are trying/avoiding etc