T09 · Insecure Skill Coding Practices
Error
- Location
- api.py:60
- Finding
- x402 Payment Verification Is Completely Bypassed## Vulnerability Details **File Location**: `api.py`, lines 60-69 and 78-103 **Vulnerability Type**: Authentication and payment authorization bypass **Risk Level**: High ### Evidence ```python def verify_x402_payment(headers: dict) -> bool: """验证x402支付""" if not X402_AVAILABLE: # 测试模式：跳过支付验证 return True # 检查 x402 相关的 header # 实际部署时需要验证支付状态 return True # 简化版本 ``` The protected endpoint also fails to invoke the verification function: ```python @app.get("/signals") async def signals( pattern: str = "all", x402: Optional[str] = Header(None) ): """ 获取A股交易信号 参数: - pattern: 形态类型 (旱地拔葱/N字型态/一阳串三阴/VCP/all) - x402: x402支付header 返回: - signals: 信号列表 - price: 价格 (USDC) - wallet: 收款钱包 """ # 这里应该添加x402支付验证 # 实际部署时需要 data = await get_signals(pattern) return { "success": True, "timestamp": datetime.now().isoformat(), "pattern": pattern, "signals": data, "price": "0.01 USDC", "wallet": "0x1a9275EE18488A20C7898C666484081F74Ee10CA", "chain": "Base (eip155:8453)" } ``` ### Technical Analysis The payment verifier returns `True` in every possible execution path. It permits access when the x402 dependency is unavailable and also unconditionally accepts requests when that dependency is installed. In addition, the `/signals` endpoint never calls the verifier. The optional `x402` request header consequently has no authorization effect. No proof is validated against the expected recipient, amount, asset, chain, nonce, payer, expiration, or transaction status. There is also no replay protection. This is a fail-open access-control design that directly contradicts the declared per-request payment requirement. ### Attack Path 1. An unauthenticated caller sends `GET /signals` or `GET /signals?p ...[truncated 847 chars]
- Remediation
- ## Remediation Suggestions - Require a payment proof for every paid endpoint and invoke verification before obtaining or returning signal data. - Cryptographically validate the proof through the supported x402 implementation. - Confirm the exact Base chain identifier, USDC asset contract, recipient address, required amount, payer authorization, expiration, and transaction finality. - Bind each proof to the requested resource and use a server-issued nonce or unique payment identifier. - Store consumed proof identifiers or transaction references to prevent replay. - Return HTTP 402 for missing, invalid, expired, underpaid, or previously consumed proofs. - Fail closed if the x402 package, network verification service, or chain validation is unavailable. Any test-mode bypass must be explicitly configured and prohibited in production. - Add automated tests covering absent headers, malformed proofs, incorrect chains, incorrect recipients, insufficient amounts, expired proofs, and replay attempts.