llamaIndex - 💡(How to fix) Fix EvaporateExtractor.run_fn_on_nodes executes LLM output with full globals [1 participants]

2. **Implement AST validation**:
   Use the `ast` module to validate the generated code and block dunder access and imports outside a small allowlist.
   ```python
import ast

def validate_ast(code):
    tree = ast.parse(code)
    for node in ast.walk(tree):
        if isinstance(node, ast.Import):
            # Check if import is in allowlist
            if node.names[0].name not in ['re']:
                raise ValueError("Invalid import")
        elif isinstance(node, ast.Attribute) and node.attr.startswith('__'):
            # Block dunder access
            raise ValueError("Dunder access is not allowed")

### Verification
To verify the fix, run the 16 unit tests provided in the PR #20676 to ensure the sandboxed environment is working correctly and the generated extraction functions are executing as expected.

### Extra Tips
* Regularly review and update the allowlist of imports to prevent potential security vulnerabilities.
* Consider using a more robust sandboxing solution, such as a separate process or container, for executing untrusted code.