GHSA-4qq2-2j2x-x62c: npm PraisonAI MCPSecurity Basic/OAuth authentication policies accept invalid credentials without validation

Summary The published npm package praisonai exports an MCPSecurity helper described in source as: MCP Security - Authentication, authorization, and rate limiting Provides security policies for MCP servers. Its AuthMethod type advertises five authentication methods: export type AuthMethod = 'none' | 'api-key' | 'bearer' | 'basic' | 'oauth'; The authentication-policy evaluator, however, only validates credentials for api-key and bearer: if (policy.auth.method === 'api-key' || policy.auth.method === 'bearer') { const valid = policy.auth.validate ? await policy.auth.validate(token) : this.validateApiKey(token); if (!valid) { return { allowed: false, reason: 'Invalid credentials' }; } } return { allowed: true, context: { authenticated: true } }; For basic and oauth, any non-empty Authorization header skips the supplied validate callback and returns allowed. A local PoV configures auth.validate to always return false; invalid api-key and bearer credentials are rejected, while invalid basic and oauth credentials are accepted without calling the validator. This is a protection-mechanism failure in the exported npm MCP security helper. It is distinct from the separate issue that the npm MCPServer HTTP transport does not enforce authentication by default. Technical Details SecurityPolicy.auth accepts both a method and a validator: auth?: { method: AuthMethod; validate?: (token: string) => Promise<boolean> }; extractToken() parses both Bearer and Basic headers: if (auth.startsWith('Bearer ')) { return auth.slice(7); } if (auth.startsWith('Basic ')) { return auth.slice(6); } return auth; But evaluatePolicy() only calls policy.auth.validate() for two methods: if (policy.auth.method === 'api-key' || policy.auth.method === 'bearer') { const valid = policy.auth.validate ? await policy.auth.validate(token) : this.validateApiKey(token); if (!valid) { return { allowed: false, reason: 'Invalid credentials' }; } } There is no validation branch for basic or oauth. Afte