When resolving a program, Python/Windows look for the current working directory, and after that the PATH environment (see big warning in https://docs.python.org/3/library/subprocess.html#popen-constructor). 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.
Details
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.
And there are other commands executed that should probably be aware of this problem.
PoC
On a Windows system, create a git.exe or git executable in any directory, and import or run GitPython from that directory
python -c "import git"
The git executable from the current directory will be run.
Impact
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.
Possible solutions
Default to an absolute path for the git program on Windows, like C:\\Program Files\\Git\\cmd\\git.EXE (default git path installation).
Require users to set the GIT_PYTHON_GIT_EXECUTABLE environment variable on Windows systems.
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.
Resolve the executable manually by only looking into the PATH environment variable (suggested by @Byron)
[!NOTE]
This vulnerability was reported via email, and it was decided to publish it here and make it public, so the community is aware of it, and a fix can be provided.
In order to resolve some git references, GitPython reads files from the .git directory, in some places the name of the file being read is provided by the user, GitPython doesn't check if this file is located outside the .git directory. This allows an attacker to make GitPython read any file from the system.
Running GitPython within any repo should work, here is an example with the GitPython repo.
import git
r = git.Repo(".")
# This will make GitPython read the README.md file from the root of the repo
r.commit("../README.md")
r.tree("../README.md")
r.index.diff("../README.md")
# Reading /etc/random
# WARNING: this will probably halt your system, run with caution
# r.commit("../../../../../../../../../dev/random")
Impact
I wasn't able to show the contents of the files (that's why "blind" local file inclusion), depending on how GitPython is being used, this can be used by an attacker for something inoffensive as checking if a file exits, or cause a DoS by making GitPython read a big/infinite file (like /dev/random on Linux systems).
Possible solutions
A solution would be to check that the final path isn't located outside the repodir path (maybe even after resolving symlinks). Maybe there could be other checks in place to make sure that the reference names are valid.
[!NOTE]
This vulnerability was reported via email, and it was decided to publish it here and make it public, so the community is aware of it, and a fix can be provided.
This issue exists because of an incomplete fix for CVE-2023-40590. On Windows, GitPython uses an untrusted search path if it uses a shell to run git, as well as when it runs bash.exe to interpret hooks. If either of those features are used on Windows, a malicious git.exe or bash.exe may be run from an untrusted repository.
Details
Although GitPython often avoids executing programs found in an untrusted search path since 3.1.33, two situations remain where this still occurs. Either can allow arbitrary code execution under some circumstances.
When a shell is used
GitPython can be told to run git commands through a shell rather than as direct subprocesses, by passing shell=True to any method that accepts it, or by both setting Git.USE_SHELL = True and not passing shell=False. Then the Windows cmd.exe shell process performs the path search, and GitPython does not prevent that shell from finding and running git in the current directory.
When GitPython runs git directly rather than through a shell, the GitPython process performs the path search, and currently omits the current directory by setting NoDefaultCurrentDirectoryInExePath in its own environment during the Popen call. Although the cmd.exe shell will honor this environment variable when present, GitPython does not currently pass it into the shell subprocess's environment.
Furthermore, because GitPython sets the subprocess CWD to the root of a repository's working tree, using a shell will run a malicious git.exe in an untrusted repository even if GitPython itself is run from a trusted location.
This also applies if Git.execute is called directly with shell=True (or after Git.USE_SHELL = True) to run any command.
When hook scripts are run
On Windows, GitPython uses bash.exe to run hooks that appear to be scripts. However, unlike when running git, no steps are taken to avoid finding and running bash.exe in the current directory.
This allows the author of an untrusted fork or branch to cause a malicious bash.exe to be run in some otherwise safe workflows. An example of such a scenario is if the user installs a trusted hook while on a trusted branch, then switches to an untrusted feature branch (possibly from a fork) to review proposed changes. If the untrusted feature branch contains a malicious bash.exe and the user's current working directory is the working tree, and the user performs an action that runs the hook, then although the hook itself is uncorrupted, it runs with the malicious bash.exe.
Note that, while bash.exe is a shell, this is a separate scenario from when git is run using the unrelated Windows cmd.exe shell.
PoC
On Windows, create a git.exe file in a repository. Then create a Repo object, and call any method through it (directly or indirectly) that supports the shell keyword argument with shell=True:
mkdir testrepo
git init testrepo
cp ... testrepo git.exe # Replace "..." with any executable of choice.
python -c "import git; print(git.Repo('testrepo').git.version(shell=True))"
The git.exe executable in the repository directory will be run.
Or use no Repo object, but do it from the location with the git.exe:
cd testrepo
python -c "import git; print(git.Git().version(shell=True))"
The git.exe executable in the current directory will be run.
For the scenario with hooks, install a hook in a repository, create a bash.exe file in the current directory, and perform an operation that causes GitPython to attempt to run the hook:
mkdir testrepo
cd testrepo
git init
mv .git/hooks/pre-commit.sample .git/hooks/pre-commit
cp ... bash.exe # Replace "..." with any executable of choice.
echo "Some text" >file.txt
git add file.txt
python -c "import git; git.Repo().index.commit('Some message')"
The bash.exe executable in the current directory will be run.
Impact
The greatest impact is probably in applications that set Git.USE_SHELL = True for historical reasons. (Undesired console windows had, in the past, been created in some kinds of applications, when it was not used.) Such an application may be vulnerable to arbitrary code execution from a malicious repository, even with no other exacerbating conditions. This is to say that, if a shell is used to run git, the full effect of CVE-2023-40590 is still present. Furthermore, as noted above, running the application itself from a trusted directory is not a sufficient mitigation.
An application that does not direct GitPython to use a shell to run git subprocesses thus avoids most of the risk. However, there is no such straightforward way to prevent GitPython from running bash.exe to interpret hooks. So while the conditions needed for that to be exploited are more involved, it may be harder to mitigate decisively prior to patching.
Possible solutions
A straightforward approach would be to address each bug directly:
When a shell is used, pass NoDefaultCurrentDirectoryInExePath into the subprocess environment, because in that scenario the subprocess is the cmd.exe shell that itself performs the path search.
Set NoDefaultCurrentDirectoryInExePath in the GitPython process environment during the Popen call made to run hooks with a bash.exe subprocess.
These need only be done on Windows.
Release Notes
gitpython-developers/GitPython (gitpython)
### [`v3.1.41`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.41): - fix Windows security issue
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.40...3.1.41)
The details about the Windows security issue [can be found in this advisory](https://togithub.com/gitpython-developers/GitPython/security/advisories/GHSA-2mqj-m65w-jghx).
Special thanks go to [@EliahKagan](https://togithub.com/EliahKagan) who reported the issue and fixed it in a single stroke, while being responsible for an incredible amount of improvements that he contributed over the last couple of months ❤️.
#### What's Changed
- Add `__all__` in git.exc by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1719](https://togithub.com/gitpython-developers/GitPython/pull/1719)
- Set submodule update cadence to weekly by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1721](https://togithub.com/gitpython-developers/GitPython/pull/1721)
- Never modify sys.path by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1720](https://togithub.com/gitpython-developers/GitPython/pull/1720)
- Bump git/ext/gitdb from `8ec2390` to `ec58b7e` by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1722](https://togithub.com/gitpython-developers/GitPython/pull/1722)
- Revise comments, docstrings, some messages, and a bit of code by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1725](https://togithub.com/gitpython-developers/GitPython/pull/1725)
- Use zero-argument super() by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1726](https://togithub.com/gitpython-developers/GitPython/pull/1726)
- Remove obsolete note in \_iter_packed_refs by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1727](https://togithub.com/gitpython-developers/GitPython/pull/1727)
- Reorganize test_util and make xfail marks precise by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1729](https://togithub.com/gitpython-developers/GitPython/pull/1729)
- Clarify license and make module top comments more consistent by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1730](https://togithub.com/gitpython-developers/GitPython/pull/1730)
- Deprecate compat.is\_, rewriting all uses by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1732](https://togithub.com/gitpython-developers/GitPython/pull/1732)
- Revise and restore some module docstrings by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1735](https://togithub.com/gitpython-developers/GitPython/pull/1735)
- Make the rmtree callback Windows-only by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1739](https://togithub.com/gitpython-developers/GitPython/pull/1739)
- List all non-passing tests in test summaries by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1740](https://togithub.com/gitpython-developers/GitPython/pull/1740)
- Document some minor subtleties in test_util.py by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1749](https://togithub.com/gitpython-developers/GitPython/pull/1749)
- Always read metadata files as UTF-8 in setup.py by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1748](https://togithub.com/gitpython-developers/GitPython/pull/1748)
- Test native Windows on CI by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1745](https://togithub.com/gitpython-developers/GitPython/pull/1745)
- Test macOS on CI by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1752](https://togithub.com/gitpython-developers/GitPython/pull/1752)
- Let close_fds be True on all platforms by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1753](https://togithub.com/gitpython-developers/GitPython/pull/1753)
- Fix IndexFile.from_tree on Windows by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1751](https://togithub.com/gitpython-developers/GitPython/pull/1751)
- Remove unused TASKKILL fallback in AutoInterrupt by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1754](https://togithub.com/gitpython-developers/GitPython/pull/1754)
- Don't return with operand when conceptually void by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1755](https://togithub.com/gitpython-developers/GitPython/pull/1755)
- Group .gitignore entries by purpose by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1758](https://togithub.com/gitpython-developers/GitPython/pull/1758)
- Adding dubious ownership handling by [@marioaag](https://togithub.com/marioaag) in [https://github.com/gitpython-developers/GitPython/pull/1746](https://togithub.com/gitpython-developers/GitPython/pull/1746)
- Avoid brittle assumptions about preexisting temporary files in tests by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1759](https://togithub.com/gitpython-developers/GitPython/pull/1759)
- Overhaul noqa directives by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1760](https://togithub.com/gitpython-developers/GitPython/pull/1760)
- Clarify some Git.execute kill_after_timeout limitations by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1761](https://togithub.com/gitpython-developers/GitPython/pull/1761)
- Bump actions/setup-python from 4 to 5 by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1763](https://togithub.com/gitpython-developers/GitPython/pull/1763)
- Don't install black on Cygwin by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1766](https://togithub.com/gitpython-developers/GitPython/pull/1766)
- Extract all "import gc" to module level by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1765](https://togithub.com/gitpython-developers/GitPython/pull/1765)
- Extract remaining local "import gc" to module level by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1768](https://togithub.com/gitpython-developers/GitPython/pull/1768)
- Replace xfail with gc.collect in TestSubmodule.test_rename by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1767](https://togithub.com/gitpython-developers/GitPython/pull/1767)
- Enable CodeQL by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1769](https://togithub.com/gitpython-developers/GitPython/pull/1769)
- Replace some uses of the deprecated mktemp function by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1770](https://togithub.com/gitpython-developers/GitPython/pull/1770)
- Bump github/codeql-action from 2 to 3 by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1773](https://togithub.com/gitpython-developers/GitPython/pull/1773)
- Run some Windows environment variable tests only on Windows by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1774](https://togithub.com/gitpython-developers/GitPython/pull/1774)
- Fix TemporaryFileSwap regression where file_path could not be Path by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1776](https://togithub.com/gitpython-developers/GitPython/pull/1776)
- Improve hooks tests by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1777](https://togithub.com/gitpython-developers/GitPython/pull/1777)
- Fix if items of Index is of type PathLike by [@stegm](https://togithub.com/stegm) in [https://github.com/gitpython-developers/GitPython/pull/1778](https://togithub.com/gitpython-developers/GitPython/pull/1778)
- Better document IterableObj.iter_items and improve some subclasses by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1780](https://togithub.com/gitpython-developers/GitPython/pull/1780)
- Revert "Don't install black on Cygwin" by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1783](https://togithub.com/gitpython-developers/GitPython/pull/1783)
- Add missing pip in $PATH on Cygwin CI by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1784](https://togithub.com/gitpython-developers/GitPython/pull/1784)
- Shorten Iterable docstrings and put IterableObj first by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1785](https://togithub.com/gitpython-developers/GitPython/pull/1785)
- Fix incompletely revised Iterable/IterableObj docstrings by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1786](https://togithub.com/gitpython-developers/GitPython/pull/1786)
- Pre-deprecate setting Git.USE_SHELL by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1782](https://togithub.com/gitpython-developers/GitPython/pull/1782)
- Deprecate Git.USE_SHELL by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1787](https://togithub.com/gitpython-developers/GitPython/pull/1787)
- In handle_process_output don't forward finalizer result by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1788](https://togithub.com/gitpython-developers/GitPython/pull/1788)
- Fix mypy warning "Missing return statement" by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1789](https://togithub.com/gitpython-developers/GitPython/pull/1789)
- Fix two remaining Windows untrusted search path cases by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1792](https://togithub.com/gitpython-developers/GitPython/pull/1792)
#### New Contributors
- [@marioaag](https://togithub.com/marioaag) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1746](https://togithub.com/gitpython-developers/GitPython/pull/1746)
- [@stegm](https://togithub.com/stegm) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1778](https://togithub.com/gitpython-developers/GitPython/pull/1778)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.40...3.1.41
### [`v3.1.40`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.40): - fix downstream CI
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.38...3.1.40)
##### What's Changed
- Add missing info in Submodule.remove docstring by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1714](https://togithub.com/gitpython-developers/GitPython/pull/1714)
- Have init script clone submodules unconditionally by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1715](https://togithub.com/gitpython-developers/GitPython/pull/1715)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.38...3.1.40
### [`v3.1.38`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.38)
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.37...3.1.38)
##### What's Changed
- Add missing assert keywords by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1678](https://togithub.com/gitpython-developers/GitPython/pull/1678)
- Make clear every test's status in every CI run by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1679](https://togithub.com/gitpython-developers/GitPython/pull/1679)
- Fix new link to license in readme by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1680](https://togithub.com/gitpython-developers/GitPython/pull/1680)
- Drop unneeded flake8 suppressions by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1681](https://togithub.com/gitpython-developers/GitPython/pull/1681)
- Update instructions and test helpers for git-daemon by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1684](https://togithub.com/gitpython-developers/GitPython/pull/1684)
- Fix Git.execute shell use and reporting bugs by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1687](https://togithub.com/gitpython-developers/GitPython/pull/1687)
- No longer allow CI to select a prerelease for 3.12 by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1689](https://togithub.com/gitpython-developers/GitPython/pull/1689)
- Clarify Git.execute and Popen arguments by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1688](https://togithub.com/gitpython-developers/GitPython/pull/1688)
- Ask git where its daemon is and use that by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1697](https://togithub.com/gitpython-developers/GitPython/pull/1697)
- Fix bugs affecting exception wrapping in rmtree callback by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1700](https://togithub.com/gitpython-developers/GitPython/pull/1700)
- Fix dynamically-set **all** variable by [@DeflateAwning](https://togithub.com/DeflateAwning) in [https://github.com/gitpython-developers/GitPython/pull/1659](https://togithub.com/gitpython-developers/GitPython/pull/1659)
- Fix small [#1662](https://togithub.com/gitpython-developers/GitPython/issues/1662) regression due to [#1659](https://togithub.com/gitpython-developers/GitPython/issues/1659) by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1701](https://togithub.com/gitpython-developers/GitPython/pull/1701)
- Drop obsolete info on yanking from security policy by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1703](https://togithub.com/gitpython-developers/GitPython/pull/1703)
- Have Dependabot offer submodule updates by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1702](https://togithub.com/gitpython-developers/GitPython/pull/1702)
- Bump git/ext/gitdb from `49c3178` to `8ec2390` by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1704](https://togithub.com/gitpython-developers/GitPython/pull/1704)
- Bump git/ext/gitdb from `8ec2390` to `6a22706` by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1705](https://togithub.com/gitpython-developers/GitPython/pull/1705)
- Update readme for milestone-less releasing by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1707](https://togithub.com/gitpython-developers/GitPython/pull/1707)
- Run Cygwin CI workflow commands in login shells by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1709](https://togithub.com/gitpython-developers/GitPython/pull/1709)
##### New Contributors
- [@DeflateAwning](https://togithub.com/DeflateAwning) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1659](https://togithub.com/gitpython-developers/GitPython/pull/1659)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.37...3.1.38
### [`v3.1.37`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.37): - a proper fix CVE-2023-41040
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.36...3.1.37)
#### What's Changed
- Improve Python version and OS compatibility, fixing deprecations by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1654](https://togithub.com/gitpython-developers/GitPython/pull/1654)
- Better document env_case test/fixture and cwd by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1657](https://togithub.com/gitpython-developers/GitPython/pull/1657)
- Remove spurious executable permissions by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1658](https://togithub.com/gitpython-developers/GitPython/pull/1658)
- Fix up checks in Makefile and make them portable by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1661](https://togithub.com/gitpython-developers/GitPython/pull/1661)
- Fix URLs that were redirecting to another license by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1662](https://togithub.com/gitpython-developers/GitPython/pull/1662)
- Assorted small fixes/improvements to root dir docs by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1663](https://togithub.com/gitpython-developers/GitPython/pull/1663)
- Use venv instead of virtualenv in test_installation by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1664](https://togithub.com/gitpython-developers/GitPython/pull/1664)
- Omit py_modules in setup by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1665](https://togithub.com/gitpython-developers/GitPython/pull/1665)
- Don't track code coverage temporary files by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1666](https://togithub.com/gitpython-developers/GitPython/pull/1666)
- Configure tox by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1667](https://togithub.com/gitpython-developers/GitPython/pull/1667)
- Format tests with black and auto-exclude untracked paths by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1668](https://togithub.com/gitpython-developers/GitPython/pull/1668)
- Upgrade and broaden flake8, fixing style problems and bugs by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1673](https://togithub.com/gitpython-developers/GitPython/pull/1673)
- Fix rollback bug in SymbolicReference.set_reference by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1675](https://togithub.com/gitpython-developers/GitPython/pull/1675)
- Remove `@NoEffect` annotations by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1677](https://togithub.com/gitpython-developers/GitPython/pull/1677)
- Add more checks for the validity of refnames by [@facutuesca](https://togithub.com/facutuesca) in [https://github.com/gitpython-developers/GitPython/pull/1672](https://togithub.com/gitpython-developers/GitPython/pull/1672)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.36...3.1.37
### [`v3.1.36`](https://togithub.com/gitpython-developers/GitPython/compare/3.1.35...3.1.36)
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.35...3.1.36)
### [`v3.1.35`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.35): - a fix for CVE-2023-41040
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.34...3.1.35)
#### What's Changed
- Bump actions/checkout from 3 to 4 by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1643](https://togithub.com/gitpython-developers/GitPython/pull/1643)
- Fix 'Tree' object has no attribute '\_name' when submodule path is normal path by [@CosmosAtlas](https://togithub.com/CosmosAtlas) in [https://github.com/gitpython-developers/GitPython/pull/1645](https://togithub.com/gitpython-developers/GitPython/pull/1645)
- Fix CVE-2023-41040 by [@facutuesca](https://togithub.com/facutuesca) in [https://github.com/gitpython-developers/GitPython/pull/1644](https://togithub.com/gitpython-developers/GitPython/pull/1644)
- Only make config more permissive in tests that need it by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1648](https://togithub.com/gitpython-developers/GitPython/pull/1648)
- Added test for PR [#1645](https://togithub.com/gitpython-developers/GitPython/issues/1645) submodule path by [@CosmosAtlas](https://togithub.com/CosmosAtlas) in [https://github.com/gitpython-developers/GitPython/pull/1647](https://togithub.com/gitpython-developers/GitPython/pull/1647)
- Fix Windows environment variable upcasing bug by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1650](https://togithub.com/gitpython-developers/GitPython/pull/1650)
#### New Contributors
- [@CosmosAtlas](https://togithub.com/CosmosAtlas) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1645](https://togithub.com/gitpython-developers/GitPython/pull/1645)
- [@facutuesca](https://togithub.com/facutuesca) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1644](https://togithub.com/gitpython-developers/GitPython/pull/1644)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.34...3.1.35
### [`v3.1.34`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.34): - fix resource leaking
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.33...3.1.34)
#### What's Changed
- util: close lockfile after opening successfully by [@skshetry](https://togithub.com/skshetry) in [https://github.com/gitpython-developers/GitPython/pull/1639](https://togithub.com/gitpython-developers/GitPython/pull/1639)
#### New Contributors
- [@skshetry](https://togithub.com/skshetry) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1639](https://togithub.com/gitpython-developers/GitPython/pull/1639)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.33...3.1.34
### [`v3.1.33`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.33): - with security fix
[Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.32...3.1.33)
##### What's Changed
- WIP Quick doc by [@LeoDaCoda](https://togithub.com/LeoDaCoda) in [https://github.com/gitpython-developers/GitPython/pull/1608](https://togithub.com/gitpython-developers/GitPython/pull/1608)
- Partial clean up wrt mypy and black by [@bodograumann](https://togithub.com/bodograumann) in [https://github.com/gitpython-developers/GitPython/pull/1617](https://togithub.com/gitpython-developers/GitPython/pull/1617)
- Disable merge_includes in config writers by [@bodograumann](https://togithub.com/bodograumann) in [https://github.com/gitpython-developers/GitPython/pull/1618](https://togithub.com/gitpython-developers/GitPython/pull/1618)
- feat: full typing for "progress" parameter in Repo class by [@madebylydia](https://togithub.com/madebylydia) in [https://github.com/gitpython-developers/GitPython/pull/1634](https://togithub.com/gitpython-developers/GitPython/pull/1634)
- Fix CVE-2023-40590 by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1636](https://togithub.com/gitpython-developers/GitPython/pull/1636)
- [#1566](https://togithub.com/gitpython-developers/GitPython/issues/1566) Creating a lock now uses python built-in "open()" method to work arou… by [@HageMaster3108](https://togithub.com/HageMaster3108) in [https://github.com/gitpython-developers/GitPython/pull/1619](https://togithub.com/gitpython-developers/GitPython/pull/1619)
##### New Contributors
- [@LeoDaCoda](https://togithub.com/LeoDaCoda) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1608](https://togithub.com/gitpython-developers/GitPython/pull/1608)
- [@bodograumann](https://togithub.com/bodograumann) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1617](https://togithub.com/gitpython-developers/GitPython/pull/1617)
- [@EliahKagan](https://togithub.com/EliahKagan) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1636](https://togithub.com/gitpython-developers/GitPython/pull/1636)
- [@HageMaster3108](https://togithub.com/HageMaster3108) made their first contribution in [https://github.com/gitpython-developers/GitPython/pull/1619](https://togithub.com/gitpython-developers/GitPython/pull/1619)
**Full Changelog**: https://github.com/gitpython-developers/GitPython/compare/3.1.32...3.1.33
Configuration
📅 Schedule: Branch creation - "" in timezone Europe/Paris, Automerge - At any time (no schedule defined).
🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.
♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
[ ] If you want to rebase/retry this PR, check this box
This PR contains the following updates:
3.1.32
->3.1.41
GitHub Vulnerability Alerts
CVE-2023-40590
Summary
When resolving a program, Python/Windows look for the current working directory, and after that the PATH environment (see big warning in https://docs.python.org/3/library/subprocess.html#popen-constructor). GitPython defaults to use the
git
command, if a user runs GitPython from a repo has agit.exe
orgit
executable, that program will be run instead of the one in the user'sPATH
.Details
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.
The execution of the
git
command happens inhttps://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/cmd.py#L277
https://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/cmd.py#L983-L996
And there are other commands executed that should probably be aware of this problem.
PoC
On a Windows system, create a
git.exe
orgit
executable in any directory, and import or run GitPython from that directoryThe git executable from the current directory will be run.
Impact
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.Possible solutions
C:\\Program Files\\Git\\cmd\\git.EXE
(default git path installation).GIT_PYTHON_GIT_EXECUTABLE
environment variable on Windows systems.GIT_PYTHON_GIT_EXECUTABLE
env var to an absolute path.PATH
environment variable (suggested by @Byron)CVE-2023-41040
Summary
In order to resolve some git references, GitPython reads files from the
.git
directory, in some places the name of the file being read is provided by the user, GitPython doesn't check if this file is located outside the.git
directory. This allows an attacker to make GitPython read any file from the system.Details
This vulnerability is present in
https://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/refs/symbolic.py#L174-L175
That code joins the base directory with a user given string without checking if the final path is located outside the base directory.
I was able to exploit it from three places, but there may be more code paths that lead to it:
https://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/repo/base.py#L605
https://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/repo/base.py#L620
https://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/index/base.py#L1353
PoC
Running GitPython within any repo should work, here is an example with the GitPython repo.
Impact
I wasn't able to show the contents of the files (that's why "blind" local file inclusion), depending on how GitPython is being used, this can be used by an attacker for something inoffensive as checking if a file exits, or cause a DoS by making GitPython read a big/infinite file (like
/dev/random
on Linux systems).Possible solutions
A solution would be to check that the final path isn't located outside the
repodir
path (maybe even after resolving symlinks). Maybe there could be other checks in place to make sure that the reference names are valid.CVE-2024-22190
Summary
This issue exists because of an incomplete fix for CVE-2023-40590. On Windows, GitPython uses an untrusted search path if it uses a shell to run
git
, as well as when it runsbash.exe
to interpret hooks. If either of those features are used on Windows, a maliciousgit.exe
orbash.exe
may be run from an untrusted repository.Details
Although GitPython often avoids executing programs found in an untrusted search path since 3.1.33, two situations remain where this still occurs. Either can allow arbitrary code execution under some circumstances.
When a shell is used
GitPython can be told to run
git
commands through a shell rather than as direct subprocesses, by passingshell=True
to any method that accepts it, or by both settingGit.USE_SHELL = True
and not passingshell=False
. Then the Windowscmd.exe
shell process performs the path search, and GitPython does not prevent that shell from finding and runninggit
in the current directory.When GitPython runs
git
directly rather than through a shell, the GitPython process performs the path search, and currently omits the current directory by settingNoDefaultCurrentDirectoryInExePath
in its own environment during thePopen
call. Although thecmd.exe
shell will honor this environment variable when present, GitPython does not currently pass it into the shell subprocess's environment.Furthermore, because GitPython sets the subprocess CWD to the root of a repository's working tree, using a shell will run a malicious
git.exe
in an untrusted repository even if GitPython itself is run from a trusted location.This also applies if
Git.execute
is called directly withshell=True
(or afterGit.USE_SHELL = True
) to run any command.When hook scripts are run
On Windows, GitPython uses
bash.exe
to run hooks that appear to be scripts. However, unlike when runninggit
, no steps are taken to avoid finding and runningbash.exe
in the current directory.This allows the author of an untrusted fork or branch to cause a malicious
bash.exe
to be run in some otherwise safe workflows. An example of such a scenario is if the user installs a trusted hook while on a trusted branch, then switches to an untrusted feature branch (possibly from a fork) to review proposed changes. If the untrusted feature branch contains a maliciousbash.exe
and the user's current working directory is the working tree, and the user performs an action that runs the hook, then although the hook itself is uncorrupted, it runs with the maliciousbash.exe
.Note that, while
bash.exe
is a shell, this is a separate scenario from whengit
is run using the unrelated Windowscmd.exe
shell.PoC
On Windows, create a
git.exe
file in a repository. Then create aRepo
object, and call any method through it (directly or indirectly) that supports theshell
keyword argument withshell=True
:The
git.exe
executable in the repository directory will be run.Or use no
Repo
object, but do it from the location with thegit.exe
:The
git.exe
executable in the current directory will be run.For the scenario with hooks, install a hook in a repository, create a
bash.exe
file in the current directory, and perform an operation that causes GitPython to attempt to run the hook:The
bash.exe
executable in the current directory will be run.Impact
The greatest impact is probably in applications that set
Git.USE_SHELL = True
for historical reasons. (Undesired console windows had, in the past, been created in some kinds of applications, when it was not used.) Such an application may be vulnerable to arbitrary code execution from a malicious repository, even with no other exacerbating conditions. This is to say that, if a shell is used to rungit
, the full effect of CVE-2023-40590 is still present. Furthermore, as noted above, running the application itself from a trusted directory is not a sufficient mitigation.An application that does not direct GitPython to use a shell to run
git
subprocesses thus avoids most of the risk. However, there is no such straightforward way to prevent GitPython from runningbash.exe
to interpret hooks. So while the conditions needed for that to be exploited are more involved, it may be harder to mitigate decisively prior to patching.Possible solutions
A straightforward approach would be to address each bug directly:
NoDefaultCurrentDirectoryInExePath
into the subprocess environment, because in that scenario the subprocess is thecmd.exe
shell that itself performs the path search.NoDefaultCurrentDirectoryInExePath
in the GitPython process environment during thePopen
call made to run hooks with abash.exe
subprocess.These need only be done on Windows.
Release Notes
gitpython-developers/GitPython (gitpython)
### [`v3.1.41`](https://togithub.com/gitpython-developers/GitPython/releases/tag/3.1.41): - fix Windows security issue [Compare Source](https://togithub.com/gitpython-developers/GitPython/compare/3.1.40...3.1.41) The details about the Windows security issue [can be found in this advisory](https://togithub.com/gitpython-developers/GitPython/security/advisories/GHSA-2mqj-m65w-jghx). Special thanks go to [@EliahKagan](https://togithub.com/EliahKagan) who reported the issue and fixed it in a single stroke, while being responsible for an incredible amount of improvements that he contributed over the last couple of months ❤️. #### What's Changed - Add `__all__` in git.exc by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1719](https://togithub.com/gitpython-developers/GitPython/pull/1719) - Set submodule update cadence to weekly by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1721](https://togithub.com/gitpython-developers/GitPython/pull/1721) - Never modify sys.path by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1720](https://togithub.com/gitpython-developers/GitPython/pull/1720) - Bump git/ext/gitdb from `8ec2390` to `ec58b7e` by [@dependabot](https://togithub.com/dependabot) in [https://github.com/gitpython-developers/GitPython/pull/1722](https://togithub.com/gitpython-developers/GitPython/pull/1722) - Revise comments, docstrings, some messages, and a bit of code by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1725](https://togithub.com/gitpython-developers/GitPython/pull/1725) - Use zero-argument super() by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1726](https://togithub.com/gitpython-developers/GitPython/pull/1726) - Remove obsolete note in \_iter_packed_refs by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1727](https://togithub.com/gitpython-developers/GitPython/pull/1727) - Reorganize test_util and make xfail marks precise by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1729](https://togithub.com/gitpython-developers/GitPython/pull/1729) - Clarify license and make module top comments more consistent by [@EliahKagan](https://togithub.com/EliahKagan) in [https://github.com/gitpython-developers/GitPython/pull/1730](https://togithub.com/gitpython-developers/GitPython/pull/1730) - Deprecate compat.is\_Configuration
📅 Schedule: Branch creation - "" in timezone Europe/Paris, Automerge - At any time (no schedule defined).
🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.
♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
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