🛡️ Sentinel: [CRITICAL] Prevent ACE by whitelisting ast.Call in DI Container

.jules/sentinel.md

@@ -4,3 +4,7 @@
 **Vulnerability:** Found an unused `_attempt_import` function in `src/codeweaver/server/mcp/server.py` that dynamically imports a module directly from unvalidated configuration (`import_module(mw.rsplit(".", 1)[0])`), leading to potential arbitrary code execution.
 **Learning:** Functions that perform dynamic imports should not be left around in the codebase if they are unused, especially if they are designed to take unvalidated strings as input.
 **Prevention:** Avoid dynamic imports based on configuration or inputs without strict whitelisting. Use tools like `semgrep` with python security rules to actively catch these patterns.
+## 2026-04-22 - Unrestricted AST Call nodes in _safe_eval_type
+**Vulnerability:** Found `ast.Call` included in the allowed nodes list of `_safe_eval_type` in `src/codeweaver/core/di/container.py` without validation, which introduces a critical Arbitrary Code Execution (ACE) vulnerability as it permits execution of any callable in the module's global namespace via `eval()`.
+**Learning:** Permitting generic `ast.Call` nodes when parsing untrusted or complex type strings dynamically evaluated via `eval()` can lead to ACE if the type string references available functions in the global scope.
+**Prevention:** Always restrict `ast.Call` nodes to a strict whitelist of explicitly required, known-safe functions (e.g., `Depends`, `Field`) when utilizing AST validation prior to dynamic evaluation.

src/codeweaver/core/di/container.py

@@ -84,7 +84,7 @@ def __init__(self) -> None:
         self._request_cache: dict[Any, Any] = {}  # Keys can be types or callables
         self._providers_loaded: bool = False  # Track if auto-discovery has run
 
-    def _safe_eval_type(self, type_str: str, globalns: dict[str, Any]) -> Any | None:
+    def _safe_eval_type(self, type_str: str, globalns: dict[str, Any]) -> Any | None:  # noqa: C901
         """Safely evaluate a type string using AST validation.
 
         Parses the type string into an AST, validates that it contains only safe
@@ -136,6 +136,20 @@ def generic_visit(self, node: ast.AST) -> None:
                 if isinstance(node, ast.Attribute) and node.attr.startswith("__"):
                     raise TypeError(f"Forbidden dunder attribute: {node.attr}")
 
+                # Security Enhancement: Prevent Arbitrary Code Execution (ACE)
+                # Allowing generic ast.Call nodes could permit execution of any callable in the global namespace.
+                # Restrict to known safe functions used in type annotations.
+                if isinstance(node, ast.Call):
+                    func_name = None
+                    if isinstance(node.func, ast.Name):
+                        func_name = node.func.id
+                    elif isinstance(node.func, ast.Attribute):
+                        func_name = node.func.attr
+
+                    allowed_calls = {"Depends", "depends", "Field", "PrivateAttr", "Tag", "Parameter"}
+                    if func_name not in allowed_calls:
+                        raise TypeError(f"Forbidden function call in type string: {func_name}")
+
                 super().generic_visit(node)
 
         try: