Re: Potential symlink attack in python3 __pycache__

[Michael Orlitzky <michael () orlitzky com>]

On Sat, 2021-07-24 at 18:33 +0300, Georgi Guninski wrote:
> Not sure if this is vulnerability, but it looks like
> classical symlink attack.
>
> In python3, if a script in directory DIR1 does "import another",
> then python3 creates directory __pycache__ in DIR1 and puts
> some files in __pycache__.
>
> According to our tests, if DIR1/__pycache__ is symlink to something,
> then python3 follows the symlink.

When subdirectories of DIR1 are writable by anyone other than the
person running the script, you have a bunch of problems:

  https://bugs.python.org/issue16202