Deserialization of Untrusted Data Affecting picklescan package, versions [,0.0.27)

picklescan is a Security scanner detecting Python Pickle files performing suspicious actions

Affected versions of this package are vulnerable to Deserialization of Untrusted Data via the STACK_GLOBAL opcode parsing process. An attacker can bypass detection mechanisms by crafting a malicious pickle file that exploits a logic flaw in argument tracking, causing the parser to mishandle arguments and trigger unexpected exceptions.

import pickle
payload = b"S'os'\nS'system'\n\x93S'ls'\n\x85R."
with open('bad_pickle.pkl', 'wb') as f:
    f.write(payload)
pickle.load(open('bad_pickle.pkl', 'rb'))

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.

• GitHub Commit
• GitHub Release
• Vulnerable Code
• Vulnerable Code