CVE-2025-71361
Picklescan has a missing detection when calling built-in python idlelib.calltip.Calltip
Description
### Summary Using idlelib.calltip.Calltip.fetch_tip, which is a built-in python library function to execute remote pickle file. ### Details The attack payload executes in the following steps: First, the attacker craft the payload by calling to idlelib.calltip.Calltip.fetch_tip function in reduce method Then when the victim after checking whether the pickle file is safe by using Picklescan library and this library doesn't dectect any dangerous functions, decide to pickle.load() this malicious pickle file, thus lead to remote code execution. ### PoC ``` class EvilCalltipFetchTip: def __reduce__(self): from idlelib.calltip import Calltip # fetch_tip(expression) -> get_entity(expression) -> eval(expression) return Calltip().fetch_tip, ("__import__('os').system('whoami')",) ``` ### Impact Who is impacted? Any organization or individual relying on picklescan to detect malicious pickle files inside PyTorch models. What is the impact? Attackers can embed malicious code in pickle file that remains undetected but executes when the pickle file is loaded. Supply Chain Attack: Attackers can distribute infected pickle files across ML models, APIs, or saved Python objects. ### Corresponding https://github.com/FredericDT https://github.com/Qhaoduoyu
How to fix CVE-2025-71361
To remediate CVE-2025-71361, upgrade the affected package to a fixed version below.
- —upgrade to 0.0.29 or later
Is CVE-2025-71361 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 0.0.29