hermes - 💡(How to fix) Fix Unsafe exec() chain in godmode scripts allows arbitrary code execution [1 comments, 2 participants]

TL;DR

To address the critical vulnerability, replace the use of exec() with importlib for loading modules and ensure proper file handling to prevent arbitrary code execution.

Guidance

• Validate the HERMES_HOME environment variable to prevent it from pointing to an attacker-controlled directory.
• Use importlib.util.spec_from_file_location and importlib.util.module_from_spec to load modules instead of exec().
• Implement path validation against expected checksums to ensure only authorized scripts are loaded.
• Modify the file opening to use a with statement, e.g., with open(path) as f:, to prevent file descriptor leaks.

Example

import importlib.util

def _gm_load(path):
    spec = importlib.util.spec_from_file_location("_godmode_module", path)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module

Notes

The provided code snippet assumes that the scripts to be loaded are valid Python modules. Additional error handling and validation may be necessary depending on the specific requirements of the application.

Recommendation

Apply the suggested workaround by replacing exec() with importlib and ensuring proper file handling to mitigate the arbitrary code execution vulnerability. This approach provides a more secure way to load and execute scripts without introducing the risks associated with exec().