Picklescan Arbitrary Code Execution Vulnerability via Detection Bypass

A vulnerability in Picklescan versions prior to 0.0.30 allows malicious pickle files to evade detection and execute arbitrary code. This issue arises from the improper handling of pickle files that exploit the 'lib2to3.pgen2.pgen.ParserGenerator.make_label' function within the 'reduce' method. Attackers can craft these pickle files to include embedded code that, while undetected by Picklescan, executes when the pickle file is loaded using 'pickle.load()'.

Impact

Exploitation of this vulnerability allows for arbitrary code execution on the system where the malicious pickle file is loaded.

Reproduction

To reproduce this vulnerability, first create a malicious pickle file that exploits the 'lib2to3.pgen2.pgen.ParserGenerator.make_label' function. This can be done by crafting a payload that, when the pickle file is loaded, executes arbitrary commands. Once the malicious pickle file is created, use Picklescan to scan it. The scan will not detect any threats. Afterward, load the pickle file using 'pickle.load()'. This will trigger the execution of the embedded code, demonstrating the vulnerability.

Remediation

Users are advised to update Picklescan to version 0.0.30 or later, where this vulnerability has been patched.