Software Supply Chain Attacks: Attack Vectors, Examples, and 6 Defensive Measures

What Are Software Supply Chain Attacks? 

Software supply chain attacks target the less-secure elements in a software supply network. These attacks exploit the trust between suppliers and customers, aiming to compromise software or hardware before it reaches the end user. By infiltrating at any stage of the supply chain, attackers gain unauthorized access to sensitive systems or data.

The complexity and interconnectivity of software supply chains make them attractive targets. As organizations often rely on third-party suppliers for various components and services, the potential for exploitation increases. These attacks can have widespread implications, affecting multiple entities down the line.

Recommended Reading: 4 Types of Cyber Threat Intelligence and Using Them Effectively.

How Does a Software Supply Chain Attack Work? 

An attacker first identifies vulnerabilities within the supply chain. This could involve targeting a third-party vendor with less stringent security measures. Once a weak link is compromised, the attacker can inject malicious code into the software or hardware being supplied to the end user.

The contaminated product, appearing legitimate, makes its way through the supply chain and is deployed within the target’s infrastructure. By the time the compromise is discovered, the attacker may have already achieved their objectives, which could include data theft, system disruption, or laying the groundwork for future attacks.

Attack Vectors in Software Supply Chain Attacks 

Attackers can exploit the following vulnerabilities to attack the software supply chain.

Compromised Dependencies

Third-party dependencies are common in software development, but they can introduce risks. If a dependency is compromised, any software that relies on it may inherit vulnerabilities. Attackers can exploit this by inserting malicious code into a widely used library or component.

Monitoring dependencies for known vulnerabilities is challenging, especially when the software ecosystem is extensive. Attackers count on oversight in these areas to spread their malware effectively throughout multiple systems. Always check the Software Bill of Materials (SBOM) and make sure you have a list of secondary dependencies in your risk register to track for publicly-announced vulnerabilities and patches.

Vulnerabilities in CI/CD Pipelines

Continuous Integration/Continuous Deployment (CI/CD) pipelines automate software delivery but can be a point of weakness. If an attacker gains access to the CI/CD pipeline, they can alter the software being deployed, injecting malware directly into the product.

Securing CI/CD pipelines requires robust access controls and regular security audits to identify and rectify vulnerabilities. Failure to do so can lead to the distribution of compromised software, affecting numerous users.

Insider Threats

Insider threats come from employees or partners who exploit their access for malicious purposes. By leveraging their trusted status, insiders can introduce vulnerabilities or malicious code without immediate detection.

Mitigating insider threats involves comprehensive access management, continual monitoring, and enforcing the principle of least privilege. Even so, the human factor remains a challenging element to fully control.

Man-in-the-Middle Attacks (MitM)

In a MitM attack, attackers intercept legitimate communications between two parties. In a software supply chain, this might involve tampering with code as it’s being transmitted or intercepting system updates and replacing them with malicious versions.

Preventive measures include encryption, secure transmission protocols, and integrity checks. However, vigilance is necessary as attackers continuously develop novel methods to intercept or disrupt communications.

Related content: Read our guide to threat hunting

Examples of Recent Supply Chain Attacks 

Here are some examples of high-profile software supply chain attacks.

Okta Supply Chain Attack

In October 2023, Okta, a well-known provider of identity and authentication management services, reported a security breach where threat actors obtained access to private customer data. The breach occurred via compromised credentials to Okta’s customer support management system, enabling unauthorized access to files uploaded by certain customers in recent support cases. 

This incident underscored Okta’s appeal as a prime target for threat actors due to its extensive access and sensitive capabilities, raising concerns about the broader implications for Okta’s customers through the supply chain.

JetBrains Supply Chain Attack

A significant vulnerability in JetBrains TeamCity servers, widely used for Continuous Integration/Continuous Deployment (CI/CD), was exploited by attackers, potentially facilitating supply chain attacks. Government officials warned about the exploitation of this critical authentication bypass vulnerability by a Russian Threat Actor, Cozy Bear, linked to the Russian Foreign Intelligence Service (SVR). 

This flaw allowed unauthenticated attackers with HTTP(S) access to execute remote code and gain administrative control over affected servers. The wide usage of TeamCity servers by large software companies heightened the risk of widespread impact​.

MOVEit Supply Chain Attack

The MOVEit supply chain attack targeted users of MOVEit Transfer, a tool for securely transferring sensitive files, and affected over 620 organizations, including prominent names such as the BBC, British Airways, and Aer Lingus. Personal identifiable information (PII) was compromised, including staff addresses and IDs. 

Ransomware group Cl0p was linked to this attack, exploiting critical vulnerabilities to cause significant damage. This attack highlighted the extensive reach and severe consequences of supply chain attacks on the security and privacy of numerous individuals​.

3CX Supply Chain Attack

The 3CX supply chain attack targeted the software supply chain of 3CX, a VoIP desktop client, by distributing maliciously altered versions of the software. These tampered versions contained a malicious library file, executing and downloading encrypted files with command and control instructions. 

Notably, the malicious apps were signed with valid 3CX certificates and distributed from 3CX’s official servers, indicating a compromise of the company’s build environment. This attack was particularly alarming due to the legitimacy of the compromised software, making detection and prevention challenging​.

6 Ways to Prevent Software Supply Chain Attacks 

Here are some crucial measures for protecting the software supply chain.

1. Secure the Development Environment

Ensuring the security of the development environment is fundamental to protecting against supply chain attacks. This involves limiting access to development tools and resources to authorized personnel only, using strong authentication methods, and encrypting sensitive data at rest and in transit. Regularly updating and patching development tools and environments can also prevent exploitation of known vulnerabilities.

2. Secure the Build Pipeline

Securing the build pipeline is essential to prevent unauthorized modifications to software during the build process. Implementing strict access controls, auditing tools, and processes within the CI/CD pipeline can help detect and prevent unauthorized changes. Additionally, signing software artifacts and using reproducible builds can ensure the integrity and authenticity of the software being delivered. Regular security assessments of the build pipeline can also identify and rectify potential vulnerabilities.

3. Vet Third-Party Components

Before integrating third-party components into software projects, it’s crucial to perform thorough security assessments. This vetting process should include reviewing the security posture of the third-party vendor, scanning the component for known vulnerabilities, and understanding the component’s update and patch management processes. Establishing a protocol for regularly reviewing and updating third-party components can help mitigate risks associated with vulnerabilities that emerge over time.

4. Utilize Software Composition Analysis (SCA) Tools

Software Composition Analysis (SCA) tools provide a comprehensive analysis of the software components used in development, including open-source libraries, frameworks, and other third-party components. These tools work by scanning the software’s codebase to identify and catalog each component and its version, and cross-reference it against vulnerability databases. Most SCA tools also provide remediation guidance for identified vulnerabilities.

5. Implement a Software Bill of Materials (SBOM)

An SBOM provides a comprehensive inventory of all components used in software, including open-source and proprietary elements. Implementing an SBOM helps organizations understand the components within their software, making it easier to identify and respond to vulnerabilities. By maintaining an accurate and up-to-date SBOM, organizations can quickly assess the impact of identified vulnerabilities and expedite remediation efforts.

6.  Use Security Information and Event Management (SIEM)

Security Information and Event Management (SIEM) systems aggregate and analyze log and event data from across the software supply chain to detect and respond to security incidents. By providing real-time visibility into system activities, SIEM systems help identify unusual behavior that may indicate a supply chain attack. Implementing SIEM solutions, along with setting up appropriate alerting mechanisms, can enhance an organization’s ability to detect and respond to attacks more swiftly and effectively.

Exabeam Platform Capabilities: SIEM, UEBA, SOAR, Insider Threats, Compliance, TDIR

The Exabeam Security Operations Platform applies AI and automation to security operations workflows for a holistic approach to combating cyberthreats against your software supply chain, delivering the most effective threat detection, investigation, and response (TDIR): 

• AI-driven detections pinpoint high-risk threats by learning normal behavior of users, service accounts, and devices, and prioritizing threats with context-aware risk scoring. 
• Automated investigations simplify security operations, correlating disparate data to create threat timelines. 
• Playbooks document workflows and standardize activity to speed investigation and response. 
• Correlation Rule templates for customizing and prioritizing incidents involving your code repositories, directory service attacks, and more.
• Visualizations map coverage against the most strategic outcomes and frameworks to close data and detection gaps. 

With these capabilities, Exabeam empowers security operations teams to achieve faster, more accurate, and consistent TDIR.