PyTorch pt2 Loading Handler Deserialization Vulnerability
Overview
PyTorch version 2.10.0 contains a critical deserialization vulnerability within its pt2 Loading Handler component. This flaw arises from improper handling of serialized data, allowing an attacker with local access to craft malicious serialized objects. When these objects are processed by the affected function, PyTorch deserializes them without sufficient validation, leading to arbitrary code execution in the context of the running Python process. The exploit vector is accessible via a publicly available exploit, indicating a significant risk of exploitation. The maintainers were notified of this issue through a pull request, but as of the reported date, no patches or fixes have been implemented. This vulnerability poses a serious threat to systems relying on PyTorch for model loading or serialization, particularly in environments where local access is not strictly controlled.
Affected Systems
Testing Guide
1. Obtain or craft a malicious serialized Python object (e.g., using `pickle` with a malicious payload). 2. Attempt to load this malicious object using `torch.load()` within a PyTorch 2.10.0 environment. 3. Monitor the system for signs of arbitrary code execution, such as unexpected process creation, file modifications, or network connections originating from the Python process.
Mitigation Steps
- Ensure only trusted serialized files are loaded into PyTorch. - Implement strict access controls to prevent unauthorized local access to systems running PyTorch 2.10.0. - Monitor system processes for unusual activity that might indicate code execution. - Consider downgrading to a stable, unpatched version of PyTorch if security is paramount and the vulnerability cannot be mitigated otherwise.