OWASP Top 10 for Mobile Apps: M6 – Insecure Authorisation

OWASP Top 10 for Mobile Apps: M6 – Insecure Authorisation

In today’s digital-first economy, mobile applications serve as the backbone for businesses, offering convenience and accessibility to consumers and employees alike. However, with the rapid proliferation of mobile apps comes the growing challenge of safeguarding sensitive data and ensuring robust cybersecurity. Among the many vulnerabilities outlined by the OWASP (Open Web Application Security Project) Top 10 for Mobile Apps, M6: Insecure Authorisation stands out as a critical issue. This blog post delves into the nuances of insecure authorisation, focusing on its implications for software developers and C-suite executives, while offering actionable insights for addressing this pervasive risk.

Understanding Insecure Authorisation

Mobile applications are a cornerstone of modern business operations and personal convenience. However, as the dependency on these apps grows, so do the associated risks.

What is Insecure Authorisation?

Insecure authorisation occurs when an application fails to properly enforce access control mechanisms, allowing unauthorised users or attackers to access resources, perform actions, or manipulate data without appropriate permissions. Unlike authentication, which verifies a user’s identity, authorisation determines what an authenticated user is allowed to do.

An insecure authorisation flaw might allow:

• Regular users to access admin-level functionalities.
• Employees to view confidential data beyond their clearance level.
• Attackers to bypass restrictions through APIs or exposed endpoints.

Why is it a Concern?

For C-suite executives, insecure authorisation translates into tangible business risks, including:

1. Data Breaches: Exposed customer or business data can lead to reputational damage and regulatory fines.
2. Financial Loss: Fraudulent transactions or unauthorised operations may result in direct monetary losses.
3. Erosion of Trust: Users may lose confidence in your app, affecting customer retention and loyalty.
4. Operational Disruption: Exploits can cause downtime and impact productivity.

For software developers, insecure authorisation signifies weak system architecture, misconfigured APIs, or improper role validation. Understanding its root causes is the first step towards mitigation.

Key Causes of Insecure Authorisation

1. Improper Role Validation

One common issue is the failure to differentiate between user roles, such as admin, regular user, or guest. For example, a poorly implemented mobile app might allow a regular user to escalate privileges by manipulating API requests.

2. Client-Side Logic for Authorisation

Storing or validating authorisation rules on the client side—within the mobile app code—can lead to easy exploitation. Attackers can reverse-engineer the app, alter the logic, and bypass restrictions.

3. Weak API Security

APIs often serve as the backbone for mobile applications. When APIs lack proper access control checks, they become a prime target for attackers aiming to exploit insecure authorisation vulnerabilities.

4. Insecure Token Management

Tokens such as OAuth, JWT, or session tokens are used for authorisation. Improper handling, such as predictable tokens or expired tokens being accepted, can open doors for unauthorised access.

Root Causes of Insecure Authorisation

Understanding the origins of this vulnerability helps developers and executives implement effective mitigation strategies:

1. Inadequate Role and Permission Management:
   • Poorly defined access control policies.
   • Hardcoding roles within the app instead of server-side validation.
2. Client-Side Enforcement of Authorisation:
   • Trusting client-side logic to enforce permissions.
   • Attackers easily bypassing such controls using tools like proxy interceptors.
3. Insecure API Design:
   • Overly permissive APIs exposing sensitive operations.
   • Failure to validate requests against user roles and permissions.
4. Lack of Testing:
   • Insufficient penetration testing or code reviews.
   • Over-reliance on automated tools without manual oversight.

Real-World Examples of Insecure Authorisation

Case Study 1: Over-permissive APIs in a Fintech App

A financial services app exposed APIs that lacked robust access controls. An attacker exploited this by altering a regular user token to access admin-level APIs, exposing sensitive customer data.

Business Impact:

• Breach of GDPR regulations resulted in a £10 million fine.
• Loss of trust led to a 20% decline in active users over six months.

Case Study 2: Privilege Escalation in an E-Commerce Platform

An e-commerce mobile app allowed users to alter their roles by tampering with request headers. A user exploited this to gain access to confidential sales reports.

Business Impact:

• Leakage of competitive insights harmed market positioning.
• Increased costs for post-breach remediation.

Case Study: Lessons from a Breach

The Incident

A global retail giant’s mobile app fell victim to insecure authorisation, allowing unauthorised users to access sensitive order details. Attackers exploited an API endpoint that failed to validate user roles properly.

The Fallout

• Data Leak: Over 10 million customer records were exposed.
• Financial Loss: The breach cost the company $150 million in fines and remediation.
• Reputational Damage: A significant drop in customer trust led to a 20% decline in sales.

The Response

The company overhauled its authorisation processes, implemented server-side validation, and conducted company-wide security training.

Examples in Real-World Scenarios

1. Insufficient Role Validation: A standard user can access administrative functions due to improper role checks.
2. Broken Object-Level Authorisation (BOLA): Users access data that they do not own, such as viewing another customer’s account details.
3. Over-Privileged API Access: An app grants users excessive permissions, exposing critical business data.

Real-World Cyber Incidents Involving M6: Insecure Authorisation

To illustrate the potential risks and impacts of insecure authorisation in mobile applications, let us examine notable real-world incidents. These cases highlight the consequences of weak authorisation mechanisms and the necessity of robust measures to prevent exploitation.

1. API Misconfiguration Leading to Data Breach in a Banking App

A global banking giant suffered a significant data breach when researchers uncovered vulnerabilities in its mobile app. The app’s API lacked robust authorisation checks, enabling unauthorised users to access customer account details.

Key Takeaway:

The absence of proper authorisation checks allowed attackers to perform unauthorised actions, such as viewing sensitive account data. This incident underscores the importance of validating permissions at every access point.

2. Ride-Sharing App’s Vulnerability Exposing User Data

A popular ride-sharing app faced criticism when researchers discovered that their mobile app allowed any logged-in user to retrieve another user’s trip details. The insecure implementation of access tokens facilitated the attack.

How It Happened:

The app relied solely on user IDs embedded in API requests for authorisation, failing to verify if the requesting user was allowed to access that data.

Impact:

The breach compromised users’ locations, trip histories, and even payment details. This created privacy risks and tarnished the company’s reputation.

3. E-commerce Platform’s Loyalty Points Exploitation

An e-commerce mobile app suffered a critical vulnerability where an insecure authorisation mechanism allowed attackers to manipulate loyalty points.

Scenario:

Attackers intercepted and modified API requests to add reward points to their accounts. The system did not validate if the requesting user had permission to perform such actions, resulting in financial losses for the business.

Business Impact:

The company had to disable its loyalty programme temporarily, reimburse legitimate users, and invest in re-engineering their authorisation systems.

4. Social Media App’s Profile Hijacking

A high-profile social media platform became a victim of insecure authorisation when attackers exploited flaws in its mobile API. The attackers could impersonate other users by modifying profile data without proper authorisation checks.

Details of the Attack:

The app failed to authenticate the ownership of the accounts being updated, allowing attackers to hijack profiles. This led to severe reputational damage, especially as some profiles belonged to public figures.

Lesson for Developers:

Multi-level authorisation checks, alongside robust auditing mechanisms, could have prevented unauthorised profile changes.

5. Healthcare App’s Unauthorised Access to Medical Records

A healthcare app exposed its patients’ sensitive medical records due to weak authorisation mechanisms. By manipulating API requests, attackers accessed the personal health information (PHI) of other users.

Implications:

This breach violated data protection regulations like GDPR and HIPAA, leading to legal penalties and a loss of trust among patients.

Common Themes and Lessons Learned

Across these incidents, several recurring issues stand out:

• API Weaknesses: APIs are often the focal point of insecure authorisation attacks. Ensuring proper permission checks on every API endpoint is critical.
• Lack of Granular Authorisation: Many apps rely on overly simplistic authorisation mechanisms, failing to account for role-based or user-specific permissions.
• Inadequate Testing: Many of these breaches could have been identified during development or penetration testing phases, highlighting the need for rigorous security testing.

Detecting Insecure Authorisation Vulnerabilities

1. Penetration Testing

Regular penetration testing can identify gaps in your authorisation mechanisms. Focus on:

• API endpoints.
• Role-based access controls.
• Token validation processes.

2. Code Reviews

Conduct in-depth reviews of both server-side and client-side code. Ensure that:

• Authorisation logic is exclusively implemented on the server side.
• API gateways enforce strict access rules.

3. Automated Security Tools

Leverage tools such as OWASP ZAP, Burp Suite, or API security platforms to identify and address insecure authorisation vulnerabilities systematically.

Strategies for Mitigation

1. Implement Role-Based Access Control (RBAC)

Adopt RBAC to define and enforce user roles clearly. For instance:

• Admin: Full access to all resources.
• Employee: Restricted to their department’s data.
• Customer: Limited to their own account details.

2. Server-Side Authorisation Logic

Authorisation rules must reside on the server, not the client. For example:

• Use middleware to validate permissions before processing requests.
• Avoid hardcoding authorisation checks within the app.

3. Secure API Design

• Validate API requests against user roles.
• Use secure authentication methods like OAuth 2.0.
• Throttle API requests to prevent brute-force attacks.

4. Token Best Practices

• Use time-bound tokens with expiration.
• Employ secure storage mechanisms for tokens, such as encrypted keychains.
• Regularly rotate keys used for token signing.

Business Impact and ROI for C-Suite Executives

The Cost of Neglect

Neglecting insecure authorisation can cost businesses dearly. Data breaches in 2023 had an average cost of £3.86 million globally. For small and medium-sized enterprises, the impact could be catastrophic.

Investing in Security

An upfront investment in robust security measures pays dividends by:

1. Reducing Downtime: Strong security minimises disruptions caused by breaches.
2. Enhancing Reputation: A secure app builds trust among users and stakeholders.
3. Ensuring Compliance: Avoid hefty fines from regulations like GDPR or PCI DSS.

Business Impact of Insecure Authorisation

Cost Implications

The financial impact of an insecure authorisation exploit can be staggering. The average cost of a data breach in 2024 stands at approximately $4.45 million globally, according to a report by IBM. For mobile apps, insecure authorisation is among the top contributors to breaches.

Compliance Risks

Regulations like the GDPR and CCPA mandate robust data protection measures. Violations due to insecure authorisation can attract penalties of up to 4% of annual turnover or €20 million, whichever is higher.

Brand Erosion

In today’s competitive landscape, trust is paramount. A single breach can cause irreversible damage to brand reputation, leading to customer churn and lost market share.

Practical Steps for Developers and C-Suite Collaboration

Developers

1. Regularly train in secure coding practices.
2. Follow OWASP guidelines meticulously.
3. Advocate for security as a priority during project planning.

C-Suite Executives

1. Allocate budgets for security audits and penetration testing.
2. Foster a culture of security awareness across the organisation.
3. Demand regular updates from development teams on security posture.

For C-Suite Executives

1. Invest in Security Training:
   • Ensure that development teams are well-versed in secure coding practices.
   • Encourage certifications like CEH, CISSP, or OWASP training.
2. Allocate Budget for Security:
   • Include robust security measures in app development budgets.
   • Fund regular penetration tests and third-party audits.
3. Monitor Compliance:
   • Appoint a Chief Information Security Officer (CISO) to oversee compliance.
   • Regularly review adherence to regulations like GDPR, CCPA, and PCI DSS.
4. Adopt Zero Trust Architecture:
   • Assume that every interaction within the system is untrusted.
   • Use multi-factor authentication and adaptive access controls to enhance security.

For Software Developers

Practical Tips for Developers

• Use Secure Frameworks: Leverage security-focused frameworks like Spring Security or OAuth 2.0 for managing authorisation.
• Monitor Access Logs: Regularly review logs for unusual access patterns to detect potential exploits.
• Implement Rate Limiting: Prevent brute force attacks by limiting the number of API requests from a single IP.

1. Implement Role-Based Access Control (RBAC):
   • Define roles clearly and assign permissions accordingly.
   • Validate roles on the server side for every request.
2. Adopt the Principle of Least Privilege (PoLP):
   • Grant users only the permissions they need to perform their tasks.
   • Regularly review and update access controls.
3. Server-Side Enforcement:
   • Use server-side logic to enforce authorisation checks.
   • Avoid relying on client-side mechanisms, which are easily bypassed.
4. Secure API Development:
   • Implement proper authentication and authorisation checks for all API endpoints.
   • Use tools like OpenAPI and Postman to test API security rigorously.
5. Associate with Penetration Testers to perform Thorough Testing:
   • Perform manual and automated penetration testing to identify gaps.
   • Use tools like Burp Suite, OWASP ZAP, and Checkmarx for comprehensive vulnerability scans.

Mitigating M6: Insecure Authorisation

Developers and organisations can adopt several measures to reduce the risk of insecure authorisation:

Best Practices:

1. Enforce RBAC: Implement fine-grained, server-side role and permission validation.
2. API Gateway Security: Use API gateways to validate requests before processing.
3. Token-Based Authorisation: Use secure tokens (e.g., JWT) with appropriate claims for access control.
4. Least Privilege Principle: Ensure users have access only to the resources they need.
5. Audit Trails: Maintain logs of authorisation attempts and regularly review them for anomalies.

Defence in Depth:

• Regular Penetration Testing: Include insecure authorisation checks as part of the security testing lifecycle.
• Security Training for Developers: Equip developers with the knowledge to implement and test robust authorisation mechanisms.
• Continuous Monitoring: Use runtime protection tools to detect and block unauthorised access attempts.

Penetration Testing Methodology for M6

Penetration testers play a crucial role in uncovering insecure authorisation vulnerabilities. The following methodology provides a structured approach to identify and exploit these flaws:

1. Information Gathering

• Analyse API Documentation: Obtain and review API documentation for endpoint descriptions and expected permissions.
• Understand the User Roles: Identify roles (e.g., admin, user, guest) and the permissions assigned to each.
• Identify Entry Points: Locate authentication and authorisation mechanisms (e.g., API keys, OAuth tokens).

2. Authentication and Session Management Analysis

• Token Validation: Inspect how tokens are generated, stored, and validated. Look for predictable tokens or weak cryptographic implementations.
• Session Expiry: Verify session expiration and re-authentication mechanisms to prevent prolonged unauthorised access.

3. Role and Privilege Testing

Horizontal Privilege Escalation:

Test if one user can access another user’s resources by modifying identifiers like user_id in API requests. Example:

http

GET /user/1234/orders

Authorization: Bearer <token>

•  Modify 1234 to another user’s ID and check the response.
  
• Vertical Privilege Escalation:
  
  Attempt to perform actions restricted to higher-privileged roles.
  
  Example:
  
  Sending requests intended for admin accounts (e.g., creating or deleting users) using a non-admin token.
  
• Endpoint Mapping:
  
  Use automated tools like Burp Suite or Postman to map and fuzz API endpoints, ensuring all access controls are properly enforced.
  

4. API Misuse Testing

• Replay Attacks: Reuse valid requests with modified payloads to bypass authorisation checks.
• Parameter Tampering: Alter parameters in API calls to exploit weak access controls.
• **Token Manipulation:**Test token verification by:
  • Removing the token.
  • Using expired tokens.
  • Forging tokens with guessed keys.

5. Client-Side Authorisation Testing

• Reverse Engineering: Use tools like APKTool or Frida to inspect the mobile app for hardcoded credentials, API keys, or hidden endpoints.
• Local Storage Inspection: Check if sensitive data like tokens or permissions are insecurely stored on the device.
• Debugging Authorisation Flows: Use dynamic analysis tools such as MITMproxy or Charles Proxy to intercept and analyse traffic between the app and backend.

6. Exploitation

• Bypass Mechanisms: Exploit endpoints without performing authentication or using minimal credentials.
• Custom Scripts: Write scripts using Python or Bash to automate repetitive tests, such as fuzzing APIs with multiple IDs or roles.
• Reporting Impact: Demonstrate real-world scenarios, such as transferring funds or accessing confidential records, to highlight risks effectively.

Tools for Penetration Testing

Penetration testers can use the following tools to identify and exploit M6 vulnerabilities:

Static Analysis Tools

• MobSF: Mobile Security Framework for reverse engineering and static analysis.
• JADX: Decompile APKs and inspect code for hardcoded credentials or insecure authorisation logic.

Dynamic Analysis Tools

• Burp Suite: Intercept and manipulate traffic between the mobile app and the server.
• Postman: Craft and test API requests for privilege escalation.

Fuzzing Tools

• Zap Proxy: Identify and fuzz vulnerable endpoints.
• OWASP ZAP: Comprehensive testing for API security flaws, including insecure authorisation.

Final Thoughts

Insecure authorisation is a critical vulnerability that poses severe risks to businesses and their customers. For software developers, adhering to best practices like RBAC, server-side enforcement, and rigorous testing can mitigate these risks. For C-suite executives, investing in security training, compliance monitoring, and adopting a Zero Trust approach ensures that vulnerabilities like M6 do not jeopardise business operations.

By prioritising secure authorisation practices, businesses can safeguard their assets, maintain customer trust, and achieve a robust return on investment in their cybersecurity initiatives. Remember, security is not a one-time effort but an ongoing commitment to resilience in an ever-evolving threat landscape.

M6: Insecure Authorisation is more than a technical vulnerability—it’s a business risk with far-reaching consequences. By understanding its causes, implications, and mitigation strategies, software developers and C-suite executives can work together to safeguard mobile applications effectively. Investing in robust security measures is not just about avoiding threats; it’s about enabling innovation and growth in a secure environment.

Prioritise security today to ensure a resilient and prosperous tomorrow. Let your mobile app not just serve your users but protect them as well.

The Business Imperative

For C-Suite executives, these incidents emphasise the importance of prioritising secure authorisation mechanisms during app development. Failing to do so not only exposes businesses to legal and reputational risks but also incurs financial losses.

Investing in secure development practices, regular audits, and advanced monitoring systems is not just a technical necessity but a strategic business decision.

For Penetration Testers

For penetration testers, insecure authorisation (OWASP Top 10 M6) represents a critical area of focus. By following systematic testing methodologies, using advanced tools, and leveraging case studies, testers can uncover vulnerabilities that could have devastating impacts on businesses. Simultaneously, educating developers and adopting industry best practices ensures that mobile applications remain secure against evolving threats.