What is a Software Supply Chain Attack?

A supply chain attack is a sophisticated form of cyberattack that exploits the inherent trust organizations place in their external partners and providers. Threat actors can gain unauthorized access to a target’s network or systems by compromising a trusted third party, often without immediate detection. This indirect and stealthy approach makes supply chain attacks one of the most dangerous tools in a cybercriminal’s arsenal.

Today, organizations and individuals alike depend heavily on third-party software, hardware, and code. When we install or use products from reputable sources, we naturally assume they are free of malicious intent. However, this inherent trust creates a vulnerability that supply chain attacks are designed to exploit.

Their ability to bypass traditional security measures makes supply chain attacks particularly insidious. Administrative users and software developers, who often have elevated access, might unwittingly introduce malicious elements into an organization’s internal network by installing compromised software or reusing tainted third-party code. This circumvents perimeter defenses designed to prevent external threats and allows attackers to strike from within.

Supply chain attacks can take many forms, each tailored to exploit different facets of technology infrastructure. For example, attackers might infiltrate a software provider to insert malicious code, which then spreads to end users during installation or updates. Alternatively, they might compromise software code repositories, leading developers to incorporate malicious code into their products unknowingly. Another method involves infecting the embedded software that controls hardware like networking equipment, servers, and end-user devices, ensuring the attack is deeply ingrained and challenging to detect.

In this article, we’ll delve deeper into the components of the software supply chain, dissect the anatomy of a supply chain attack, explore the risks posed by open-source and technology supply chains, and discuss strategies for mitigating these risks and securing the software development process.

Skip to: 

• What is a software supply chain?
• The anatomy of a supply chain attack
• The open-source risk in supply chain attacks
• Technology supply chain risk
• Mitigating supply chain risk
• Securing the software development supply chain

What is a software supply chain?

Modern software development processes rely on code reuse to build systems rapidly and cost-effectively. By leveraging existing code, developers can quickly assemble a system with its needed components instead of coding the entire solution from a blank canvas.

Typically, programmers either reuse internally developed software code or leverage third-party libraries and frameworks. These components and their dependencies form part of the software supply chain. In other words, a software supply chain is a list of elements that go into or affect the code from development to production. 

Almost every software application or service we use today leverages a software supply chain. For example, Netflix and Uber use Node.js, an open-source, server-side JavaScript platform well-suited for scalable applications. Similarly, WordPress, the content management system that powers almost 40% of the world’s websites, is another example of a widely used platform within the software supply chain. 

Besides leveraging the frameworks and platforms mentioned, software developers also use code libraries to build their solutions. Services like GitHub and StackOverflow are valuable resources where developers can find libraries, code snippets, and advice to help them create solutions. 

However, the concept of a software supply chain extends beyond just software development. It also encompasses instances where organizations install and run third-party applications within their technology environments. Take email, for example—nearly every organization uses third-party email software because developing an in-house solution would be both inefficient and costly.

The same applies to system monitoring, file sharing, security, and other essential functions within a technology environment. All these third-party applications, along with the external code integrated into custom-developed software, constitute an organization’s software supply chain.

The Anatomy of a Supply Chain Attack

A supply chain attack infects the third-party technologies organizations use. It then leverages this unauthorized access to infiltrate and attack its primary targets. Supply chain attacks typically start when threat actors exploit a vulnerability to access a supplier’s systems. Once they have gained entry, they embed malicious code into the supplier’s software or hardware with a particular payload.

The threat actor then waits until the target organization or user runs the supplier’s infected software or installs its infected hardware. As this infiltration technique circumvents any perimeter security, its indirect attack methodology is highly effective. It also successfully gains access to secure environments, as these attacks typically target less secure elements in the supply chain.

Supply chain attacks are not a new type of threat, but recent cases have raised their prominence in the public domain. Take the 2013 Target data breach, for example. In this case, attackers exploited a third-party refrigeration vendor's access to install malware on Target's Point of Sale (POS) systems, ultimately stealing credit card information from millions of customers. 

Another significant example is the famous Stuxnet malware that nation-states used to sabotage Iran’s nuclear centrifuges in 2010. In this example, the attackers used the digital certificates of Realtek Semiconductor to make their malware look legitimate to system administrators and evade anti-virus.  

More recently, in the SolarWinds supply chain attack, threat actors deployed malware during a routine update that emanated from SolarWinds’ servers. Every organization that ran the update was subsequently compromised, including technology companies and secure government agencies. As a result of this attack, the United States sanctioned Russia, believing that the Kremlin played a role in this mass infiltration. 

Other recent supply chain attacks, such as the narrowly averted PHP backdoor and the Code Dev incident, underscore the ongoing threat of supply chain attacks. These examples illustrate how this technique has successfully breached even the most secure environments, with far-reaching consequences. A single undetected compromise can ripple across thousands of users and organizations, demonstrating the profound impact of a successful supply chain attack.

The Open-Source Risk in Supply Chain Attacks

Most organizations incorporate open-source software into their operations in some capacity. With open-source code found in 90% of modern applications, this crucial element of the software development ecosystem is increasingly vulnerable to supply chain attacks. The recent PHP backdoor incident is a stark reminder of this risk.

Modern software applications frequently reuse open-source libraries, frameworks, and code snippets, making them attractive targets for threat actors due to their often lower security measures. According to the 2020 Sonatype State of the Software Supply Chain Report, next-generation attacks increased by 430% in the previous 12 months, highlighting the growing threat. 

Unlike commercial software, which is typically supported by dedicated security teams, the security of open-source software depends largely on the community. While open-source projects benefit from collective oversight, it ultimately falls on the organizations using the software to perform regular analysis, security audits, and penetration tests to safeguard their systems.

Technology Supply Chain Risk

The technology supply chain includes hardware and software. Although this article focuses on software supply chain attacks, organizations cannot ignore the hardware risk. Numerous examples of mobile devices arriving with embedded malware and compromised networking equipment used to breach secure networks highlight this threat. 

These instances illustrate that business and technology leaders must consider their entire technology ecosystem when assessing their supply chain risk. As threat actors have shown they can infiltrate hardware vendors, global software corporations, and open-source code repositories, organizations need a comprehensive security strategy. A supply chain attack could come from multiple vectors, and enterprises must cover all their bases. 

Mitigating Supply Chain Risk

Mitigating the risk of a supply chain attack requires a defense-in-depth strategy. Organizations must conduct comprehensive security assessments and implement multiple protective measures to minimize this risk. Many regulatory frameworks, such as PCI DSS, explicitly address supply chain risk, emphasizing the importance of regularly assessing third parties to ensure compliance with contractual obligations.

Security testing should be a critical component of any technology deliverable, and organizations must enforce this requirement on their suppliers. By holding vendors accountable for the safety of their products, organizations can enforce contractual terms if vendors fail to meet their obligations. Beyond vendor testing, organizations should also conduct internal security testing and continuous monitoring. This layered approach helps identify any vulnerabilities that vendors might have overlooked.

However, enforcing contractual terms is not an option when leveraging open-source software. As many open-source technologies come with set licensing terms, it compounds the problem even further. Organizations must also consider the legal and infringement risks associated with these licenses while protecting themselves from potential supply chain attacks.

In such cases, leveraging a Software Composition Analysis (SCA) tool like Finite State can significantly mitigate the risks associated with open-source software. Since the responsibility for testing and validating open-source components falls on the organization, an SCA tool provides an essential defensive layer, helping to identify and address potential vulnerabilities.

According to Gartner, supply chain information security should focus on safeguarding data, IT infrastructure, products, and operations. Enterprises today must deploy a wide array of defensive technologies and processes, including firewalls, intrusion detection and prevention systems, segmented networks, and vulnerability scanners, to protect their IT landscape. However, these solutions primarily guard against external threats. Organizations must also ensure that these platforms are configured to detect and respond to internal anomalies, which could indicate a successful supply chain attack.

For additional protection, enterprises may consider air-gapping critical systems to reduce supply chain risk. While disconnecting applications and networks from the internet can lower the risk of compromise, it is not always practical or foolproof. The Stuxnet attack mentioned earlier, for instance, successfully breached an air-gapped system, highlighting the limitations of this approach. 

Securing the software development supply chain

Supply chain attacks exploit the weaker links within complex systems. As modern technology solutions increasingly rely on reusable components, threat actors focus on these elements to bypass traditional security measures. 

While organizations have historically focused on defending against external threats, the rise in supply chain attacks shows a shift in tactics. Attackers now infiltrate both hardware and software supply chains, highlighting the need for robust security controls, particularly in software development.

The Finite State platform is designed to mitigate the risk of software supply chain attacks from development through to production. By identifying risks early in the software development lifecycle, Finite State empowers developers to address security issues before they become critical. During the build process, the platform assesses software components for vulnerabilities, ensuring that insecure code never makes it to production.

However, securing an application doesn’t end with its release. Software vulnerabilities are continually being discovered, whether by researchers or malicious actors. Finite State addresses this ongoing risk with its monitoring and alerting capabilities, keeping organizations protected against newly identified vulnerabilities even after the application is in production.

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