As mobile applications continue to shape modern business and personal experiences, securing them against emerging threats has become more critical than ever. Among the top risks identified in the OWASP Mobile Top 10, one issue stands out for its widespread impact yet often invisible nature – Inadequate Supply Chain Security.
Classified as the second most critical mobile app risk (M2), supply chain vulnerabilities arise when third-party components, development tools, or distribution processes are compromised. These hidden threats can introduce malicious code, expose sensitive user data, and undermine the integrity of mobile applications – often without detection until significant damage is done.
Brief Overview of OWASP Mobile Top 10 and M2
The OWASP Mobile Top 10 is universally acknowledged as the point of reference for the direst security threats endangering mobile applications. OWASP prepares this list after collecting and analyzing data from various security experts and organizations globally.
M2: Inadequate Supply Chain Security is the second most significant risk. This category includes exploiting vulnerabilities placed by third-party developers, a breach in secured libraries and SDKs, careless development or distribution methods, and so forth.
Why Mobile Apps Are Especially Vulnerable to Supply Chain Risks
Mobile apps are uniquely exposed to supply chain risks for several reasons:
- Heavy Reliance on Third-Party Code: Modern mobile apps frequently incorporate third-party libraries, SDKs, and frameworks to accelerate development. Each external component increases the attack surface, as attackers can exploit vulnerabilities in these dependencies.
- Distributed Development and Deployment: Mobile apps are often developed by distributed teams and deployed across various app stores, making it harder to control and monitor every aspect of the supply chain.
Importance of Securing Mobile Supply Chains Today
Securing the mobile app supply chain has never been more critical:
- Rising Threat Landscape: Supply chain attacks are growing, with attackers increasingly targeting third-party components and development pipelines to compromise apps at scale.
- Severe Business Impact: The consequences of a supply chain breach can be devastating, including data theft, malware infections, reputational damage, financial loss, legal penalties, and loss of customer trust.
Link to Series Pillar Post (for full OWASP Mobile Top 10 context)
To comprehensively grasp mobile app security risks and their measures, it is necessary to begin with OWASP Mobile’s Top 10 internationally accepted practices for classifying and alleviating the most significant risks mobile applications face today. This enables developers, security experts, and enterprises to focus their efforts and resources efficiently and enhances the overall mobile application security ecosystem.
Understanding the Mobile App Supply Chain
The supply chain of a mobile application involves numerous components, aids, and methodologies that are fundamentally pertinent to the conception, construction, and circulation of its tools. Similar to the supply chain for tangible commodities, it encompasses all constituents: the starting materials (SDKs, code, and libraries) to finishing the development processes (building and developing) and servicing the app stores and other distribution channels.
What Makes Up a Mobile App Supply Chain?
A mobile app supply chain includes all components, tools, and processes that span the entirety of a mobile application’s life cycle. This framework contains third-party SDKs, APIs, open-source libraries, CI/CD pipelines, build scripts, automation tools, and app distribution systems such as Google Play and the Apple Store.
Third-party SDKs, APIs, open-source libraries
Modern mobile apps rely heavily on third-party software development kits (SDKs), application programming interfaces (APIs), and open-source libraries. These components provide essential functionalities like analytics, payment processing, and social media integration, allowing developers to accelerate development and enhance app features. External dependency introduces potential risks.
CI/CD pipelines, build scripts, and automation tools
Continuous Integration and Continuous Delivery (CI/CD) pipelines have become foundational in modern mobile app development. These automated workflows handle everything from code integration and testing to building and deploying apps. Tools like Jenkins, GitHub Actions, Bitrise, and Fastlane streamline these processes, but they also represent potential attack vectors.
Key components of a mobile CI/CD pipeline include:
- Version control systems (e.g., Git).
- Automated build and testing systems.
- Code quality and security analysis tools.
- Artifact management and deployment automation.
App distribution platforms (Google Play, Apple App Store)
Mobile applications are available through official apps, including Google Play and the Apple App Store. These platforms function as the last step in the distribution chain by providing a marketplace where users can conveniently access, download, and maintain their apps. Each store has its policies regarding review, approval, and security procedures. The differences in their stringency impact the overall security posture of the distributed apps.
Trust vs. Verification: Why Most Fail
Many organizations operate under the assumption that trusted third-party components, tools, and platforms are inherently secure. This misplaced trust often leads to a lack of rigorous verification and security checks. Attackers exploit this gap by targeting weak links in the supply chain-such as insecure open-source libraries or compromised build scripts-to inject malicious code, backdoors, or spyware into mobile apps.
How the Supply Chain Expands the Mobile Attack Surface
Integrating numerous third-party components and automated development tools significantly expands the mobile app attack surface. Each dependency library, SDK, or CI/CD tool can raise vulnerabilities or be manipulated to introduce malicious functionality. As a result, attackers have more entry points to exploit, increasing the risk of data breaches, malware infections, unauthorized access, and even complete system compromise.
The growing complexity and interconnectivity of the mobile app supply chain mean that a single compromised element can have far-reaching consequences, impacting not only individual apps but also the broader ecosystem and user trust.
Real-World Impact of Inadequate Supply Chain Security
Inadequate supply chain security poses a growing threat to the mobile ecosystem. As mobile apps increasingly rely on third-party components, automated build systems, and external vendors, attackers have found new opportunities to compromise apps at scale. The consequences are not just technical breaches that can result in data theft, malware infections, reputational damage, financial loss, and regulatory penalties.
Examples of Breaches
Inadequate supply chain security has led to numerous high-profile breaches and incidents affecting millions of users worldwide. These breaches often stem from vulnerabilities or malicious behavior embedded in third-party SDKs, compromised CI/CD pipelines, or app store manipulation. Following are some notable real-world examples.
Malicious SDKs in popular apps
The most high-profile examples involve the SourMint SDK, a malicious software development kit from the Chinese ad network Mintegral. For years, this SDK functioned as expected and was widely used by thousands of developers. Suddenly, it was updated to include code that harvested user data and redirected users, impacting over 1,200 iOS apps with billions of installs. Similarly, the Vungle advertising library and Vitamio Multimedia SDK, both integrated into popular apps, were found to have vulnerabilities that enabled remote code execution and privilege escalation. See SourMint: Malicious code, ad fraud, and data leak in iOS
Dependency confusion and CI/CD hijacking
Attackers have exploited the concept of dependency confusion by publishing malicious packages with the same names as internal dependencies used by organizations. When automated build systems (CI/CD pipelines) inadvertently pull these malicious packages, attackers gain a foothold in the app’s codebase. A related risk is CI/CD hijacking, where attackers compromise build scripts or automation tools to inject malicious code during the app build process, often without detection.
Repackaging and App Store manipulation attacks
Repackaging attacks involve cloning a legitimate app, adding malicious payloads, and uploading the imposter to official app stores. The Barcode Scanner Android app incident is a notable example: attackers cloned the app, inserted code to redirect users to custom ads, and successfully distributed the malicious version via Google Play, infecting thousands of devices.
Case Studies
- Corrupdate Vulnerability: This supply-chain flaw impacted the Samsung Account and GALAXY apps on over 100 million devices. Attackers could replace official app updates with malicious APKs over an adjacent network, demonstrating how a single vulnerability can threaten millions of users. See 100 Million Samsung Galaxy Phones Vulnerable Due to Corrupdate Flaw – The Hacker News
- Event-Stream Incident: In 2018, an attacker injected malicious code into the widely used Node.js library event-stream. This code was then distributed downstream to countless apps, leading to data theft and highlighting how a compromised dependency can have far-reaching effects.
Hidden Risks in Vendor-Provided SDKs
Vendor-provided SDKs are often trusted by developers and integrated without thorough security reviews. These SDKs can introduce hidden risks:
- Delayed Malicious Updates: As seen with SourMint, an SDK can operate benignly for years before a malicious update is pushed, catching developers and users off guard.
- Lack of Transparency: Vendors may not disclose all changes or vulnerabilities in their SDKs, making it difficult for developers to assess risk or respond quickly to threats.
Common Vulnerability Patterns
Mobile app supply chains are complex, involving numerous third-party components, tools, and processes. This complexity introduces a variety of vulnerabilities that attackers can exploit, often with far-reaching consequences. The following are some of the most common vulnerability patterns that plague mobile app supply chains today.
Outdated or Deprecated SDKs
Many mobile apps rely on third-party SDKs and libraries to accelerate development and add features. Using outdated or deprecated SDKs is a leading cause of vulnerabilities. These components may contain unpatched security flaws that attackers can exploit to gain unauthorized access, inject malicious code, or compromise user data.
Lack of SBOM (Software Bill of Materials) and Visibility
A Software Bill of Materials (SBOM) is a formal record of all components, libraries, and dependencies used in an application. Without an SBOM, organizations lack visibility into what’s inside their apps, making it difficult to identify vulnerable or malicious components. This blind spot allows outdated, insecure, or compromised dependencies to persist undetected, increasing the risk of supply chain attacks.
Missing or Improper Code Signing
Code signing is a critical security measure that verifies the authenticity and integrity of app binaries. Missing or improperly implemented code signing allows attackers to tamper with applications, inject malicious code, or distribute counterfeit versions. Users may unknowingly install compromised apps, leading to data breaches or malware infections.
Excessive Permissions and API Exposure
Apps that request more permissions than necessary or expose APIs without adequate security controls significantly expand the attack surface. Overprivileged apps can leak sensitive user data, enable unauthorized access, or facilitate privilege escalation attacks. Adhering to the principle of least privilege, granting only the permissions required for core functionality, helps minimize these risks.
No Vetting or Weak Due Diligence on Third-Party Code
Adding third-party code without sufficient screening poses a significant risk. Malicious code or even neglected libraries and SDKs can stealthily install an app’s backdoors, spyware, or other vulnerabilities. Developers must properly work on every piece of external code, monitoring its changes, performing security checks, and even conducting tests to ensure it poses no risk to the code.
Insecure or Poorly Segmented CI/CD Systems
CI/CD pipelines automate the building, testing, and deployment of mobile apps, but if these pipelines are insecure or lack proper segmentation, attackers can hijack the process. Compromised build scripts, exposed credentials, or shared environments can allow malicious actors to inject harmful code or manipulate app binaries before release. Isolating build environments and enforcing strict access controls are critical defences.
Blind Trust in Vendor Updates
Unquestioningly trusting vendor updates or automatic SDK/library upgrades can introduce new vulnerabilities or malicious code. Attackers may compromise a vendor’s distribution channel, or legitimate updates may inadvertently introduce bugs. Organizations should validate and test all updates in a secure environment before deploying them to production rather than assuming all vendor-supplied code is safe.
Popular Attack Techniques
Mobile app supply chains are constantly threatened by various sophisticated attack techniques. As apps increasingly rely on third-party code, automated build processes, and complex deployment pipelines, attackers have developed specialized methods to infiltrate, manipulate, and exploit these environments. Some of the most prevalent attack techniques targeting mobile app supply chains follow.
Dependency Confusion Attacks
Dependency confusion attacks take advantage of how software people manage packages. The attacker will upload a malicious module to public repositories with the same name as the internal dependency. If the public dependency is of a higher version or prioritized, it will be fetched into the build process, enabling the execution of malicious code. This attack is especially problematic because it can circumvent the more traditional security measures that would have otherwise contained the harm, and even small apps and organizations would be affected.
Typosquatting and SDK Impersonation
Typosquatting involves registering packages or SDKs with names very similar to popular legitimate ones, often differing by just a single character. Developers who mistype a package name or fail to notice the subtle difference may inadvertently include the malicious version in their app. SDK impersonation goes a step further, with attackers creating fake SDKs that mimic the behaviour and interfaces of trusted ones, making them harder to detect.
Malicious SDK Injection
Attackers may inject malicious code directly into third-party SDKs by compromising the vendor or distributing counterfeit versions. Once integrated, these SDKs can perform various harmful activities, such as stealing sensitive data, tracking users, or enabling remote app control. Because SDKs are often trusted and widely reused, a single compromised SDK can impact thousands of apps and millions of users.
CI/CD Pipeline Hijacking
Continuous Integration/Continuous Deployment (CI/CD) pipelines automate mobile app building, testing, and deployment. If attackers compromise these pipelines through exposed credentials, vulnerable plugins, or misconfigured scripts, they can inject malicious code during the build process.
Repackaging, Side-loading (Android Focus)
Repackaging attacks involve cloning a legitimate app, modifying it (often to include malware), and redistributing it through unofficial channels or even official app stores. Side-loading, which is more common on Android, refers to installing apps from sources outside the official Google Play Store. Both techniques bypass standard security reviews and expose users to significant risks, as maliciously repackaged apps can steal data, display intrusive ads, or gain unauthorized device access.
API Supply Chain Poisoning
API supply chain poisoning targets the APIs that mobile apps depend on for core functionality. Attackers may compromise third-party APIs or the infrastructure hosting them, injecting malicious responses or manipulating data in transit. This can lead to data leaks, unauthorized access, or the execution of harmful commands within the app, especially if the app lacks robust input validation and security controls.
Detection & Monitoring Challenges
The complexity and opacity of modern mobile app supply chains create significant hurdles for effectively detecting and monitoring security threats. Attackers exploit these blind spots, embedding malicious code, backdoors, or spyware in third-party components, leading to data breaches, unauthorized access, and reputational damage. We break down organizations’ core challenges in securing their mobile app supply chains.
Obfuscated or Encrypted SDK Behaviors
Many third-party SDKs use code obfuscation or encryption to protect intellectual property or prevent reverse engineering. While this can deter causal Analysis, it makes it extremely difficult for security teams to inspect SDK behaviour for malicious or risky activities. Attackers leverage this by hiding spyware, backdoors, or data exfiltration routines within obfuscated code, evading static and dynamic Analysis tools.
Limited Runtime Visibility into Third-Party Actions
Mobile apps often integrate numerous third-party libraries and SDKs, each with its runtime behaviours. Most organizations lack the tools or telemetry to monitor what these components do once the app runs on a user’s device. This limited visibility means that unauthorized data access, network calls, or dynamic code execution by third-party components can go undetected, increasing the risk of exploitation.
Dynamic Code Loading Risks
Some SDKs and libraries load code dynamically at runtime – downloading new modules or updates outside the standard app review process. This practice allows attackers to bypass app store vetting and inject malicious payloads after deployment. Detecting such activity is challenging, as the malicious code may not exist during initial security reviews or static Analysis, surfacing only during specific runtime conditions.
Weak Dev → QA → Prod Telemetry
A lack of robust telemetry across the development, QA, and production environments hampers early detection of supply chain threats. Without continuous monitoring and consistent logging throughout these stages, suspicious behaviours or unauthorized changes can slip through undetected. This weak telemetry makes it challenging to trace the origin of incidents or respond quickly to emerging threats.
Over-reliance on Vendor Trust
Many organizations assume that well-known vendors or popular SDKs are inherently secure, leading to complacency in vetting and monitoring third-party code. This blind trust is dangerous-attackers have successfully compromised trusted vendors or injected malicious updates into widely used SDKs. Without independent verification and ongoing monitoring, organizations may not realize their apps are compromised until after a breach.
Prevention & Mitigation Strategies
Securing the mobile app supply chain starts with robust dependency management. Modern apps often rely on a complex web of third-party and open-source libraries, each introducing potential vulnerabilities if not properly managed. The following are proven strategies to help organizations prevent and mitigate supply chain risks.
Secure Dependency Management
Dependencies form the backbone of modern applications in a software-driven world. Libraries, frameworks, APIs, and third-party tools dramatically speed up development but also expand the attack surface. Without secure dependency management, even the best-coded applications can become vulnerable.
Let’s explore secure dependency management, why it matters, common risks, and best practices for keeping your software supply chain safe.
Maintain an up-to-date SBOM
A Software Bill of Materials (SBOM) is a comprehensive inventory of all your mobile application’s components, libraries, and dependencies. Maintaining an up-to-date SBOM is critical for several reasons:
- It provides visibility into direct and transitive dependencies, helping you understand your entire dependency tree.
- It supports license compliance by tracking the legal requirements of each dependency.
Use automated dependency scanning tools
Automated tools are essential for identifying vulnerabilities, outdated components, and license issues within your dependencies. Leading solutions like Snyk, Dependabot, and Renovate can:
- Continuously scan your codebase for known security flaws in direct and indirect dependencies.
- Alert you to new vulnerabilities as they are discovered in public databases.
Verify the authenticity of third-party libraries
Not all third-party libraries are created equal; some may be compromised or malicious. To verify authenticity:
- Source libraries only from trusted repositories and official package managers.
- Check cryptographic signatures or hashes where available to confirm integrity.
- Avoid downloading dependencies from unofficial or unverified sources.
Strengthen CI/CD Security
As CI/CD pipelines become the backbone of modern mobile app development, their security is paramount. A compromised pipeline can allow attackers to inject malicious code, steal secrets, or disrupt releases, with consequences reaching production and end users. The following are key strategies to harden your CI/CD environment and reduce supply chain risk.
Enforce signed commits and builds
Enforcing signed commits and builds ensures the integrity and authenticity of code throughout the development lifecycle. By requiring developers to sign their commits cryptographically, teams can verify the origin of code changes and prevent unauthorized or malicious modifications from entering the pipeline. Similarly, signing build artifacts guarantees that only trusted, verified code is released to production, protecting against tampering and supply chain attacks.
Integrate SAST and DAST early in development
Embedding security testing early in the CI/CD process, called “shifting left”, is a foundational best practice. Static Application Security Testing (SAST) analyzes source code for vulnerabilities before the application is built, while Dynamic Application Security Testing (DAST) examines running applications for exploitable issues. Integrating SAST and DAST into automated pipelines ensures that vulnerabilities are detected and remediated before code reaches production, reducing the risk of deploying insecure software.
Role-Based Access Control for build systems
Implementing role-based access control (RBAC) in your CI/CD systems is essential for minimizing the risk of unauthorized access and privilege escalation. RBAC ensures that users and automated processes have only the permissions necessary for their roles, adhering to the principle of least privilege. Combine RBAC with strong authentication (such as multi-factor authentication), regular audits, and secure secrets management to further reduce risk and maintain strict control over sensitive pipeline operations.
Validate and Monitor Third-Party Code
Integrating third-party code into mobile apps is common, but it also introduces significant security risks. Validating and monitoring these components is crucial to prevent vulnerabilities and ensure the integrity of your app. The following are strategies for effectively validating and monitoring third-party code.
Sandbox and analyze third-party SDKs
Before integrating any third-party SDK into your app, thoroughly analysing its behaviour in a controlled environment is essential. Following is how:
- Sandboxing: Set up a sandbox environment to run the SDK without affecting your main app or production systems. This allows you to observe its behaviour, network interactions, and potential data access patterns without risk.
- Static Analysis: Use tools like MobSF or SAST to examine the SDK’s code for vulnerabilities, hardcoded secrets, or suspicious logic.
Require clear security documentation and disclosure
When integrating third-party components, insist on clear security documentation from vendors. This should include:
- Vulnerability Disclosure: Vendors should provide transparent information about known vulnerabilities and their mitigation strategies.
- Security Updates: Regularly review and apply security patches or updates vendors provide.
Monitor runtime behavior of integrated components
Monitoring the runtime behaviour of third-party components is critical for detecting potential security issues or unauthorized activities.
- Network Monitoring: Use tools like HTTP Toolkit or Charles Proxy to monitor network requests made by third-party SDKs. This helps identify suspicious traffic patterns or unauthorized data transmissions.
- App Performance Monitoring: Implement comprehensive app performance monitoring tools to track how third-party components affect app stability and user experience.
Restrict Distribution Sources
Restricting distribution sources is a foundational strategy for reducing mobile app supply chain risks. By ensuring your app is only published through verified stores and maintaining strict control over release channels, you significantly limit the risk of users downloading tampered or malicious versions.
Only publish via verified stores and maintain control over release channels
- Use Official App Stores: Distribute your mobile apps exclusively through official, trusted app stores such as Google Play and the Apple App Store. These platforms implement robust security measures, including app screening, code signing, and malware scanning, which help protect users from malicious or repackaged apps.
- Block Unknown Sources: For Android, you can enforce device policies that block installations from unknown sources, ensuring users cannot sideload apps from unofficial or potentially unsafe repositories.
Organizational Best Practices
Securing the mobile app supply chain is not just a technical challenge. It requires strong organizational commitment and well-defined processes. Implementing best practices at the managerial level ensures that supply chain risks are managed proactively and systematically. The following are key practices organizations should adopt to strengthen the defences against supply chain threats.
Maintain a Third-Party Risk Management Policy
Establish a comprehensive third-party risk management (TPRM) policy that defines how your organization evaluates, approves, and monitors third-party components and vendors. This policy should:
- Set clear criteria for vendor selection and ongoing assessment.
- Define responsibilities for risk ownership and mitigation.
- Include requirements for security documentation, audits, and compliance.
Conduct Regular Supply Chain Audits
Perform periodic audits of your mobile app supply chain to identify vulnerabilities and compliance gaps. Audits should cover:
- Inventory and verification of third-party libraries, SDKs, and APIs.
- Review of CI/CD pipeline security configurations and access controls.
- Assessment of app distribution practices and release channel integrity.
Integrate Supply Chain Risks into Threat Modeling
Incorporate supply chain risks explicitly into your threat modeling exercises. This means:
- Mapping all third-party dependencies and their trust boundaries.
- Identifying potential attack vectors related to supply chain components.
- Evaluating the impact and likelihood of supply chain compromise scenarios.
Train Developers on Third-Party Risks
Educate your development teams about the risks associated with third-party code and supply chain attacks. Training should cover:
- Common supply chain attack techniques and warning signs.
- Best practices for vetting and integrating third-party libraries.
- Secure coding standards related to dependency management.
Align Procurement with Secure SDLC Practices
Ensure that your procurement processes align with your Secure Software Development Lifecycle (SDLC). This includes:
- Requiring security assessments and certifications from vendors before purchase.
- Including security clauses and compliance requirements in contracts.
- Coordinating between procurement, security, and development teams to evaluate risks.
Plan Incident Response Playbooks for Supply Chain Breaches
Prepare specific incident response (IR) playbooks that address supply chain breaches. These playbooks should:
- Define roles and responsibilities for responding to supply chain incidents.
- Include procedures for identifying, containing, and eradicating compromised components.
- Outline communication plans with vendors, customers, and regulators.
Regulatory & Ecosystem Standards
Mobile app supply chain security has become a critical concern as attacks exploiting third-party components and development processes increase in frequency and sophistication. Regulatory bodies, industry standards, and app marketplaces are responding with guidelines and requirements to improve transparency, risk management, and secure development practices.
NIST SSDF and Executive Order 14028
The NIST Secure Software Development Framework (SSDF) provides a set of practices for building secure software, emphasizing:
- Supply chain risk management: Identify and address risks from third-party components.
- SBOM maintenance: Maintain a Software Bill of Materials to track dependencies.
Executive Order 14028 (Improving the Nation’s Cybersecurity) mandates federal agencies and contractors to:
- Adopt secure development practices aligned with NIST SSDF.
- Provide SBOMs for all software sold to the government.
Google Play and App Store Requirements for SDK Transparency
Both Google Play and Apple’s App Store have introduced stricter requirements to improve supply chain security:
- Google Play now requires developers to disclose and keep this information up to date about all third-party SDKs used in their apps. Google also audits SDKs for security and privacy risks and may restrict or remove apps that use non-compliant or malicious SDKs.
- Apple App Store enforces similar transparency, requiring developers to declare SDKs and third-party frameworks and to comply with privacy “nutrition labels.” Apple may reject or delist apps that use insecure or unapproved components.
Industry Push Toward SBOM Adoption and Secure Packaging
There is a strong industry movement toward:
- SBOM adoption: Maintaining an up-to-date SBOM is becoming a baseline requirement for regulatory compliance and marketplace approval. SBOMs enable rapid vulnerability response and support transparency across the software lifecycle.
- Secure packaging and distribution: Developers are encouraged (and sometimes required) to use cryptographically signed packages, secure update mechanisms, and validated distribution channels to prevent tampering and supply chain attacks.
Conclusion
The security of mobile application supply chains is no longer a niche concern – it is a shared responsibility that spans developers, organizations, and vendors alike. Every third-party library, SDK, build pipeline, and distribution channel represents a potential risk if not rigorously secured and continuously monitored.
It is essential to shift security left – embedding secure practices early in the development lifecycle – and to monitor right by maintaining strong runtime visibility and operational defenses post-deployment. Visibility into “invisible” risks like third-party behaviors, hidden dependencies, and dynamic code injections must become a priority, not an afterthought.
Proactive supply chain security measures are the foundation for user trust, regulatory compliance, and brand resilience. Contact SecureLayer7 to learn how our end-to-end Mobile App Supply Chain Security Solutions can help you detect hidden risks, fortify your supply chain, and stay a step ahead of attackers.
