Identification Failures in Feathersjs with Basic Auth

Identification failures occur when an API fails to accurately establish and enforce the identity of a requestor. In FeathersJS applications that rely on HTTP Basic Authentication, this risk arises from a mismatch between how Basic Auth credentials are transmitted and how FeathersJS authenticates and associates those credentials with a user identity. Basic Auth sends credentials in an Authorization header as base64(username:password). While base64 is not encryption, credentials are exposed in transit without TLS and can be leaked in logs or via referrer headers.

FeathersJS does not provide built-in authentication; it expects integrations (e.g., @feathersjs/authentication) to manage identity. When Basic Auth is implemented naively, the framework may treat the raw header as proof of identity without validating scope, role, or session linkage. This enables horizontal IDOR if one user’s token is mapped to another’s identity due to weak user lookup logic. It also enables vertical privilege escalation if role claims embedded in the token or derived from Basic Auth credentials are not verified against an authoritative source on each request. Common implementation patterns that exhibit this include using the decoded payload directly to query the user service without verifying ownership or scope boundaries.

The 12 security checks in middleBrick operate in parallel and include Authentication, BOLA/IDOR, BFLA/Privilege Escalation, and Unsafe Consumption. These checks validate whether identification logic consistently maps credentials to the correct subject and enforces least privilege. For LLM/AI Security, the scanner checks for system prompt leakage and active prompt injection, which can expose administrative endpoints or override user context when identification is weak. Output scanning further ensures that tokens or session identifiers are not inadvertently surfaced in responses or logs.

To illustrate a typical vulnerable setup, consider a FeathersJS service that decodes Basic Auth and uses the username to fetch a user record. If the lookup does not scope the query to the authenticated subject or does not validate a stable identifier, an attacker can manipulate the Authorization header to assume another identity:

// Vulnerable FeathersJS authentication hook (do not use)
const { AuthenticationError } = require('@feathersjs/errors');
const { Buffer } = require('buffer');

module.exports = function () {
  return async context => {
    const header = context.headers.authorization || '';
    const match = header.match(/^Basic\s+(.+)$/i);
    if (!match) {
      throw new AuthenticationError('Missing Basic Auth header');
    }
    const decoded = Buffer.from(match[1], 'base64').toString('utf-8');
    const [username, password] = decoded.split(':');
    // WARNING: No validation of password correctness against a secure store in this example
    const user = await context.app.service('users').getByUsername(username);
    if (!user) {
      throw new AuthenticationError('Invalid credentials');
    }
    context.params.user = user;
    return context;
  };
};

This pattern risks Identification Failures because it trusts the decoded username without verifying credentials against a secure store, and it does not enforce scope or role checks on each request. An attacker who discovers or guesses another username can modify the Authorization header to access that user’s resources if the service later performs lookups without scoping to the authenticated identity. middleBrick’s Authentication and BOLA/IDOR checks surface these gaps by comparing runtime behavior against the OpenAPI spec definitions and runtime calls, highlighting missing authorization boundaries.

Additionally, if Basic Auth is used without TLS, credentials can be intercepted, leading to token replay or session fixation. Even with TLS, if tokens or session identifiers derived from Basic Auth are stored insecurely or reflected in responses, the risk of data exposure increases. The Data Exposure and Encryption checks in middleBrick validate whether responses inadvertently disclose credentials or tokens, while the Encryption check ensures transit protection is indicated where applicable.

In summary, Identification Failures with FeathersJS and Basic Auth stem from inadequate credential validation, missing scope enforcement, and improper mapping of identities to requests. Attack patterns include credential leakage, IDOR via weakly scoped lookups, and privilege escalation through unchecked role claims. Security tooling that correlates spec definitions with runtime behavior is effective at detecting these gaps.

Remediation focuses on strict credential verification, scoping identity lookups, and avoiding exposure of sensitive data. Always terminate TLS in front of FeathersJS so that credentials are not exposed in transit. Do not rely on base64 encoding as protection; treat the Authorization header as opaque and validate credentials against a secure backend on every request.

Implement a custom authentication hook that validates credentials against a secure user store and enforces role and ownership checks before attaching user data to the context. Use constant-time comparison for password verification and ensure that user references are scoped to prevent IDOR:

// Secure FeathersJS authentication hook with Basic Auth
const { AuthenticationError } = require('@feathersjs/errors');
const { compare } = require('bcrypt');

module.exports = function (options = {}) {
  return async context => {
    const header = context.headers.authorization || '';
    const match = header.match(/^Basic\s+(\S+)$/i);
    if (!match) {
      throw new AuthenticationError('Missing Basic Auth header');
    }
    const decoded = Buffer.from(match[1], 'base64').toString('utf-8');
    const [username, password] = decoded.split(':');
    if (!username || !password) {
      throw new AuthenticationError('Invalid credentials format');
    }
    // Retrieve user by username (ensure index on username)
    const user = await context.app.service('users').getByUsername(username);
    if (!user) {
      throw new AuthenticationError('Invalid credentials');
    }
    // Verify password using a secure hash
    const valid = await compare(password, user.passwordHash);
    if (!valid) {
      throw new AuthenticationError('Invalid credentials');
    }
    // Enforce scope: ensure requests refer to the authenticated user
    if (context.id && context.id !== user.id) {
      // Example for BOLA/IDOR prevention: reject mismatched resource IDs
      throw new AuthenticationError('Unauthorized resource access');
    }
    // Attach minimal user context, excluding secrets
    context.params.user = {
      id: user.id,
      username: user.username,
      role: user.role
    };
    return context;
  };
};

To mitigate Identification Failures further, apply role-based access control (RBAC) within service hooks or a centralized authorization layer. Validate roles on each request rather than relying on static claims. For endpoints that act on behalf of a user, ensure that the subject of the request maps exactly to the authenticated identity:

// Authorization hook example for scoped access
module.exports = function () {
  return async context => {
    const { user } = context.params;
    if (!user) {
      throw new Error('Authentication required');
    }
    // For user-specific endpoints, enforce ownership
    if (context.method === 'get' && typeof context.id !== 'undefined') {
      if (context.id !== user.id) {
        throw new AuthenticationError('Forbidden: resource does not belong to user');
      }
    }
    // Apply role checks for admin operations
    if (context.data && context.data.isAdmin && user.role !== 'admin') {
      throw new AuthenticationError('Insufficient permissions');
    }
    return context;
  };
};

middleBrick’s Pro plan supports continuous monitoring and CI/CD integration, which can enforce security thresholds in pipelines and alert on regressions in identification logic. Its GitHub Action can fail builds if risk scores degrade, while the CLI allows quick scans from the terminal to validate remediation effectiveness. The MCP Server enables scanning directly from AI coding assistants to catch identification flaws during development.

Finally, rotate credentials and invalidate sessions on privilege changes. Avoid logging Authorization headers or responses that echo tokens. Use security headers to limit exposure (e.g., strict Transport Security). Regularly review your OpenAPI spec against runtime behavior; discrepancies often reveal identification gaps that align with OWASP API Top 10 A07:2023 — Identification and Authentication Failures.