GHSA-wfm5-v35h-vwf4
Vulnerability from github
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 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.
The execution of the git command happens in
https://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 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_EXECUTABLEenvironment 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_EXECUTABLEenv var to an absolute path. - Resolve the executable manually by only looking into the
PATHenvironment 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.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.1.32"
},
"package": {
"ecosystem": "PyPI",
"name": "gitpython"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.33"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-40590"
],
"database_specific": {
"cwe_ids": [
"CWE-426"
],
"github_reviewed": true,
"github_reviewed_at": "2023-08-29T23:33:53Z",
"nvd_published_at": "2023-08-28T18:15:08Z",
"severity": "HIGH"
},
"details": "### Summary\n\nWhen 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\u0027s `PATH`.\n\n### Details\n\nThis is more of a problem on how Python interacts with Windows systems, Linux and any other OS aren\u0027t affected by this. But probably people using GitPython usually run it from the CWD of a repo.\n\nThe execution of the `git` command happens in\n\nhttps://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/cmd.py#L277 \n\nhttps://github.com/gitpython-developers/GitPython/blob/1c8310d7cae144f74a671cbe17e51f63a830adbf/git/cmd.py#L983-L996\n\nAnd there are other commands executed that should probably be aware of this problem.\n\n### PoC\n\nOn a Windows system, create a `git.exe` or `git` executable in any directory, and import or run GitPython from that directory\n\n```\npython -c \"import git\"\n```\n\nThe git executable from the current directory will be run.\n\n### Impact\n\nAn 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.\n\n### Possible solutions\n \n- Default to an absolute path for the git program on Windows, like `C:\\\\Program Files\\\\Git\\\\cmd\\\\git.EXE` (default git path installation).\n- Require users to set the `GIT_PYTHON_GIT_EXECUTABLE` environment variable on Windows systems.\n- 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.\n- Resolve the executable manually by only looking into the `PATH` environment variable (suggested by @Byron)\n\n---\n\n\u003e [!NOTE]\n\u003e 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.",
"id": "GHSA-wfm5-v35h-vwf4",
"modified": "2023-08-29T23:33:53Z",
"published": "2023-08-29T23:33:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-wfm5-v35h-vwf4"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-40590"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/issues/1635"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/pull/1636"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/commit/8b75434e2c8a082cdeb4971cc6f0ee2bafec45bc"
},
{
"type": "WEB",
"url": "https://docs.python.org/3/library/subprocess.html#popen-constructor"
},
{
"type": "PACKAGE",
"url": "https://github.com/gitpython-developers/GitPython"
},
{
"type": "WEB",
"url": "https://github.com/gitpython-developers/GitPython/releases/tag/3.1.33"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/gitpython/PYSEC-2023-161.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "GitPython untrusted search path on Windows systems leading to arbitrary code execution"
}