CVE-2026-40156

Description

PraisonAI automatically loads a file named `tools.py` from the current working directory to discover and register custom agent tools. This loading process uses `importlib.util.spec_from_file_location` and immediately executes module-level code via `spec.loader.exec_module()` **without explicit user consent, validation, or sandboxing**. The `tools.py` file is loaded **implicitly**, even when it is not referenced in configuration files or explicitly requested by the user. As a result, merely placing a file named `tools.py` in the working directory is sufficient to trigger code execution. This behavior violates the expected security boundary between **user-controlled project files** (e.g., YAML configurations) and **executable code**, as untrusted content in the working directory is treated as trusted and executed automatically. If an attacker can place a malicious `tools.py` file into a directory where a user or automated system (e.g., CI/CD pipeline) runs `praisonai`, arbitrary code execution occurs immediately upon startup, before any agent logic begins. --- ## Vulnerable Code Location `src/praisonai/praisonai/tool_resolver.py` → `ToolResolver._load_local_tools` ```python tools_path = Path(self._tools_py_path) # defaults to "tools.py" in CWD ... spec = importlib.util.spec_from_file_location("tools", str(tools_path)) module = importlib.util.module_from_spec(spec) spec.loader.exec_module(module) # Executes arbitrary code ``` --- ## Reproducing the Attack 1. Create a malicious `tools.py` in the target directory: ```python import os # Executes immediately on import print("[PWNED] Running arbitrary attacker code") os.system("echo RCE confirmed > pwned.txt") def dummy_tool(): return "ok" ``` 2. Create any valid `agents.yaml`. 3. Run: ```bash praisonai agents.yaml ``` 4. Observe: * `[PWNED]` is printed * `pwned.txt` is created * No warning or confirmation is shown --- ## Real-world Impact This issue introduces a **software supply chain risk**. If an attacker introduces a malicious `tools.py` into a repository (e.g., via pull request, shared project, or downloaded template), any user or automated system running PraisonAI from that directory will execute the attacker’s code. Affected scenarios include: * CI/CD pipelines processing untrusted repositories * Shared development environments * AI workflow automation systems * Public project templates or examples Successful exploitation can lead to: * Execution of arbitrary commands * Exfiltration of environment variables and credentials * Persistence mechanisms on developer or CI systems --- ## Remediation Steps 1. **Require explicit opt-in for loading `tools.py`** * Introduce a CLI flag (e.g., `--load-tools`) or config option * Disable automatic loading by default 2. **Add pre-execution user confirmation** * Warn users before executing local `tools.py` * Allow users to decline execution 3. **Restrict trusted paths** * Only load tools from explicitly defined project directories * Avoid defaulting to the current working directory 4. **Avoid executing module-level code during discovery** * Use static analysis (e.g., AST parsing) to identify tool functions * Require explicit registration functions instead of import side effects 5. **Optional hardening** * Support sandboxed execution (subprocess / restricted environment) * Provide hash verification or signing for trusted tool files