🛡️ Sentinel: [CRITICAL] Fix Internal Error Leakage via API Responses in MCP Server

[davidruzicka]

🚨 Severity: CRITICAL
💡 Vulnerability: The MCP server JSON-RPC handlers for prompts/get, resources/read, and completion/complete were catching raw runtime and logic exceptions and leaking the un-sanitized error message string directly to the client in the error.message field of the JSON-RPC response.
🎯 Impact: An attacker or regular client could receive sensitive internal server details, such as database error messages, paths, or service configuration specifics, increasing the attack surface.
🔧 Fix: The catch blocks have been updated to securely sanitize these messages using the existing this.formatErrorForClient(error, correlationId) method, which prevents leakage of internal errors while passing through "safe" client-facing validation messages. A unique correlation ID is generated and logged alongside the raw error stack trace to allow safe internal debugging.
✅ Verification: Updated src/mcp/mcp-server-apps.test.ts to assert that the message string correctly incorporates the correlation UUID via regex and that validation errors correctly format. All unit and e2e tests were passed using npm run test.

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PR created automatically by Jules for task 3979447730811687819 started by @davidruzicka

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

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