Bug 1214734 (CVE-2023-40590)

CVE-2023-40590

 GitPython is a python library used to interact with Git repositories. When
resolving a program, Python/Windows look for the current working directory, and
after that the PATH environment. GitPython defaults to use the `git` command, if
a user runs GitPython from a repo has a `git.exe` or `git` executable, that
program will be run instead of the one in the user's `PATH`. This is more of a
problem on how Python interacts with Windows systems, Linux and any other OS
aren't affected by this. But probably people using GitPython usually run it from
the CWD of a repo. An attacker can trick a user to download a repository with a
malicious `git` executable, if the user runs/imports GitPython from that
directory, it allows the attacker to run any arbitrary commands. There is no fix
currently available for windows users, however there are a few mitigations. 1:
Default to an absolute path for the git program on Windows, like `C:\\Program
Files\\Git\\cmd\\git.EXE` (default git path installation). 2: Require users to
set the `GIT_PYTHON_GIT_EXECUTABLE` environment variable on Windows systems. 3:
Make this problem prominent in the documentation and advise users to never run
GitPython from an untrusted repo, or set the `GIT_PYTHON_GIT_EXECUTABLE` env var
to an absolute path. 4: Resolve the executable manually by only looking into the
`PATH` environment variable.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-40590
https://www.cve.org/CVERecord?id=CVE-2023-40590
https://docs.python.org/3/library/subprocess.html#popen-constructor
https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-wfm5-v35h-vwf4