Identification Failures on Aws

Identification failures in Aws applications create critical security vulnerabilities that allow attackers to impersonate legitimate users or systems. In Aws-based applications, these failures typically manifest through improper handling of AWS credentials, session management, and identity verification mechanisms.

The most common manifestation occurs when Aws Lambda functions or API Gateway endpoints fail to properly validate caller identity. Consider a scenario where an API Gateway endpoint trusts the Authorization header without verifying the associated AWS IAM principal. An attacker can craft requests with arbitrary headers, causing the backend to process requests as if they came from a legitimate user.

// Vulnerable: No identity verification
app.get('/user-profile', (req, res) => {
  const userId = req.headers['x-user-id'] || 'default';
  db.getUserProfile(userId).then(profile => res.json(profile));
});

This pattern becomes particularly dangerous in multi-tenant Aws architectures where resources are shared across different accounts or organizations. Without proper identification checks, one tenant can access another's data simply by manipulating request parameters.

Another critical manifestation involves STS (Security Token Service) token misuse. When Aws applications generate temporary credentials for cross-service access but fail to bind those credentials to specific users or contexts, attackers can reuse stolen tokens. This is especially problematic in microservices architectures where services assume roles across different AWS accounts.

// Vulnerable: STS token not properly scoped
const sts = new AWS.STS();
sts.assumeRole({
  RoleArn: 'arn:aws:iam::123456789012:role/ReadOnly',
  RoleSessionName: 'session1' // No user identification
}, (err, data) => {
  if (err) throw err;
  // Token can be used by anyone who obtains it
});

Cognito identity pools present another attack surface when improperly configured. If identity pool roles aren't correctly scoped to authenticated users, an attacker can modify the IdentityId parameter to access other users' data stored in S3 or DynamoDB.

Detecting identification failures in Aws environments requires specialized tools that understand Aws's unique authentication and authorization mechanisms. middleBrick's Aws-specific scanning identifies these vulnerabilities through several targeted approaches.

For Lambda functions, middleBrick analyzes the execution context to verify that functions properly validate the caller's identity. It checks whether Lambda functions use context.identity or context.authorizer properties to authenticate requests before processing sensitive operations. The scanner also verifies that IAM policies attached to Lambda functions follow the principle of least privilege.

API Gateway endpoints are examined for proper integration of Aws Cognito or custom authorizers. middleBrick tests whether endpoints properly reject requests with missing or malformed authentication headers, and whether they correctly parse and validate JWT tokens issued by Aws services.

# Scan an Aws API Gateway endpoint
middlebrick scan https://abcdef123456.execute-api.us-east-1.amazonaws.com/prod/user

The scanner specifically tests for BOLA (Broken Object Level Authorization) vulnerabilities that are common in Aws applications. It manipulates resource identifiers in API requests to determine if the application properly verifies that the requester owns or has permission to access the requested resource.

For Aws S3 and DynamoDB operations, middleBrick verifies that applications don't rely on client-provided identifiers without proper authorization checks. It tests whether S3 bucket policies and DynamoDB IAM roles are correctly scoped to prevent unauthorized data access.

Remediating identification failures in Aws applications requires leveraging Aws's native security features and following Aws security best practices. The key is implementing proper identity verification at every layer of your application stack.

For API Gateway endpoints, implement custom authorizers or use Aws Cognito user pools with proper JWT validation. The authorizer should verify the token's signature, expiration, and scope before allowing access to backend resources.

// Secure: Using Cognito authorizer with proper validation
const { verify } = require('jsonwebtoken');
const AWS = require('aws-sdk');
const cognitoIdentity = new AWS.CognitoIdentityServiceProvider();

exports.handler = async (event) => {
  const token = event.headers.Authorization.split(' ')[1];
  
  try {
    const decoded = verify(token, process.env.JWT_SECRET);
    const user = await cognitoIdentity.getUser({
      AccessToken: token
    }).promise();
    
    // Verify user identity matches requested resource
    if (user.Username !== event.pathParameters.userId) {
      return { statusCode: 403, body: 'Forbidden' };
    }
    
    return { statusCode: 200, body: await getUserData(user.Username) };
  } catch (error) {
    return { statusCode: 401, body: 'Unauthorized' };
  }
};

For Lambda functions that need to access other Aws services, use IAM roles with proper trust policies and avoid passing credentials through function parameters. Implement resource-level permissions using IAM policies with conditions.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": ["dynamodb:GetItem"],
      "Resource": "arn:aws:dynamodb:us-east-1:123456789012:table/Users",
      "Condition": {
        "ForAllValues:StringEquals": {
          "dynamodb:LeadingKeys": ["${aws:username}"]
        }
      }
    }
  ]
}

When using Aws STS for temporary credentials, always include the RoleSessionName with identifiable information and use external IDs when trusting roles across accounts. This creates an auditable trail and prevents token reuse.

// Secure: STS with proper scoping
const sts = new AWS.STS();
sts.assumeRole({
  RoleArn: 'arn:aws:iam::123456789012:role/ReadOnly',
  RoleSessionName: `user-${userId}-${Date.now()}`,
  ExternalId: process.env.EXTERNAL_ID
}, (err, data) => {
  if (err) throw err;
  // Use data.Credentials for service access
});

For S3 and DynamoDB operations, implement server-side encryption with customer-managed keys (SSE-KMS) and use IAM policies that restrict access based on user identity. Always validate that the requesting user has permission to access the specific resource being requested.