PraisonAI has unsafe tool resolution in ToolExecutionMixin.execute_tool: undeclared __main__ callables execute
Summary
praisonaiagents resolves unresolved tool names against module globals and __main__ after it fails to match the declared tool list and the registry. With the default agent configuration, _perm_allow is None, so undeclared non-dangerous tool names are not rejected by the permission gate. An attacker who can influence tool-call names can therefore invoke unintended application callables that were never declared as tools.
Details
The vulnerable resolution path is in [[tool_execution.py](https://github.com/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/praisonaiagents/agent/tool_execution.py:734)](/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/praisonaiagents/agent/tool_execution.py:734). After searching declared tools and the registry, execution falls back to globals() and then __main__:
```python
func = None
for tool in self.tools if isinstance(self.tools, (list, tuple)) else []:
...
if func is None:
try:
from ..tools.registry import get_registry
registry = get_registry()
func = registry.get(function_name)
except ImportError:
pass
if func is None:
func = globals().get(function_name)
if not func:
import __main__
func = getattr(__main__, function_name, None)
```
If a callable is found, it is executed directly:
```python
elif callable(func):
casted_arguments = self._cast_arguments(func, arguments)
return func(**casted_arguments)
```
The permission gate does not enforce a declared-tool allowlist by default. In [[tool_execution.py](https://github.com/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/praisonaiagents/agent/tool_execution.py:550)](/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/praisonaiagents/agent/tool_execution.py:550), execution is only rejected if _perm_allow is non-None:
```python
if self._perm_deny and function_name in self._perm_deny:
return {"error": f"Tool '{function_name}' blocked by permission policy", "permission_denied": True}
if self._perm_allow is not None and function_name not in self._perm_allow:
return {"error": f"Tool '{function_name}' not in allowed tools list", "permission_denied": True}
```
Default agent initialization sets _perm_allow = None, which means "allow all" rather than "allow only declared tools" in [[agent.py](https://github.com/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/praisonaiagents/agent/agent.py:1749)](/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/praisonaiagents/agent/agent.py:1749):
```python
self._perm_deny = frozenset() # Permission tier deny set (empty = no denials)
self._perm_allow = None # Permission tier allow set (None = allow all)
```
The project's own tests confirm that default agents have no allowlist and that undeclared custom tool names pass approval:
- [
[test_permissions.py](https://github.com/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/tests/unit/test_permissions.py:56)](/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/tests/unit/[test_permissions.py](https://github.com/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/tests/unit/test_permissions.py:142):56) asserts that a default Agent has _perm_allow is None. - [
test_permissions.py](/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents/tests/unit/test_permissions.py:142) explicitly checks that agent._check_tool_approval_sync("my_custom_tool", {}) passes for an undeclared tool name.
Empirical verification:
I verified the bypass locally on commit d8a8a786915dc67a7c3021e24f72458f2eac5d9c (v4.6.35) by defining a callable only in __main__, giving the agent an empty tools list, and invoking execute_tool() with that undeclared name. The tool executor ran the __main__ function anyway.
PoC
Environment
- Repo:
MervinPraison/PraisonAI - Commit:
d8a8a786915dc67a7c3021e24f72458f2eac5d9c - Verified against PyPI package versions available on May 3, 2026:
praisonaiagents 1.6.35PraisonAI 4.6.35- Python 3
Steps
1. From the repository root, run:
```bash
python3 - <<'PY'
import sys
from unittest.mock import MagicMock, patch
sys.path.insert(0, '/Users/shmulc/Documents/Codex/2026-05-03/please-go-over-tmp-tp-advisories/repos/PraisonAI/src/praisonai-agents')
from praisonaiagents.agen
