T09 · Insecure Skill Coding Practices
Warning
- Location
- x402_cli.py:197
- Finding
- Undefined Runtime Type Annotation Prevents CLI Startup<![CDATA[ ## Vulnerability Details **File Location**: `x402_cli.py:197-204` **Vulnerability Type**: Availability failure caused by an undefined runtime annotation **Risk Level**: Medium ### Vulnerable Code ```python def _x402_request( x402_client: x402ClientSync, url: str, request_header: Optional[Dict[str, Any]] = None, request_type: str = "post", request_data: Optional[Dict[str, Any]] = None, timeout: int = 60, ) -> Tuple[int, Dict[str, Any]]: ``` ### Technical Analysis `x402ClientSync` is neither defined in the module nor imported from a dependency. The file also does not enable postponed evaluation through `from __future__ import annotations`. Consequently, Python evaluates the annotation while defining `_x402_request` and raises `NameError` during module loading. This occurs before `main()` runs and before the CLI can emit its documented structured error response. The issue renders all commands unavailable, including commands that do not perform payments, such as `discover list`, `discover search`, and `request info`. ### Attack Path 1. A user or Agent invokes any command, such as: ```bash python x402_cli.py discover list ``` 2. Python imports and evaluates the module. 3. Execution reaches the `_x402_request` function definition. 4. Python attempts to resolve `x402ClientSync`. 5. Because the name is undefined, module loading terminates with `NameError`. 6. The requested operation never executes, and the documented JSON output contract is bypassed. No attacker-controlled input is required; this is an unconditional availability defect. ### Impact Assessment - Complete denial of service for all advertised CLI functionality. - Discovery, endpoint inspection, and payment operations cannot execute. - Automation expecting one JSON object receives an unstructured interpreter exception instead. - No additional system privilege is obtained by an attacker. - The sensitive network and payment paths are unreachable in the audi ...[truncated 49 chars]
- Remediation
- <![CDATA[ ## Remediation Suggestions 1. Replace `x402ClientSync` with the imported and correct client type if `x402Client` is intended: ```python def _x402_request( x402_client: x402Client, ... ) -> Tuple[int, Dict[str, Any]]: ``` 2. Alternatively, import the intended synchronous client class explicitly. 3. Consider adding: ```python from __future__ import annotations ``` This prevents immediate annotation evaluation, but it should not substitute for using the correct type. 4. Add startup and smoke tests that import the module and execute every parser path. 5. Add static type checking to CI so undefined annotation names fail before release. ]]>