Supply Chain Attacks: How Enterprises Can Close the Vendor Security Gap

Why Supply Chain Attacks Are So Hard to Detect

Supply chain attacks differ from conventional intrusions because the malicious activity often arrives through legitimate channels that enterprises already trust.

Instead of exploiting a firewall or phishing an employee directly, attackers compromise software vendors, managed service providers, code repositories or third-party integrations that already possess authorized access. That makes detection significantly harder.

“When an attacker compromises a trusted software component or vendor tool, the malicious activity arrives inside your environment wrapped in something you have already decided to trust,” says Martin Zugec, technical solutions director at Bitdefender. 

How Software Dependencies Become Back Doors

Modern enterprise software depends heavily on open-source libraries, APIs, and third-party code. Most applications are assembled from hundreds or even thousands of interconnected dependencies rather than written entirely in-house — a sprawling dependency ecosystem with a major attack surface.

“A typical application might have ten declared dependencies,” says Adam Winston, vice president of endpoint security and managed detection and response at WatchGuard Technologies. “Those ten carry five hundred more — invisible to most developers, unaudited by most security teams.” 

Attackers increasingly exploit those hidden relationships by compromising maintainers, injecting malicious code into legitimate updates, or abusing integrations granted excessive permissions.

Kirsten Newcomer, senior director of product and security strategy for hybrid platforms at Red Hat, says organizations frequently introduce risk by integrating third-party dependencies without sufficiently validating them before deployment.

“All content should be verified prior to deployment,” she explains. 

That includes validating signatures, encrypting connections, scanning dependencies before integration and continuously reassessing components as vulnerabilities emerge over time.

LEARN MORE: How managed detection and response services can improve your cybersecurity.

Manufacturing's OT Legacy Is a Supply Chain Liability

Manufacturing organizations face especially difficult supply chain security challenges because operational technology environments often prioritize uptime and interoperability over security modernization.

Many industrial systems were designed for longevity rather than continuous patching or segmentation. Vendor access may remain persistent for years, while production downtime creates strong incentives against taking systems offline for security updates.

“There is a dangerous myth in industrial sectors that ‘old and stable’ means ‘secure,’” Winston cautions. 

The physical nature of manufacturing environments raises the stakes further. Supply chain risk extends beyond software into embedded controllers, industrial sensors, logistics providers, and operational technology vendors supporting production systems.

“A breach at any one of them can bring an entire factory floor to a halt,” Winston says.

Defending Against Third- and Fourth-Party Risk

Many organizations still lack clear visibility into which vendors can access specific systems, what permissions those vendors possess, and how downstream fourth-party dependencies connect into the broader environment.

“You cannot manage risk you cannot see,” Zugec says. 

Security teams are shifting toward continuous monitoring models tracking vendor activity, reviewing access patterns, identifying unusual behavior and reassessing risk dynamically instead of relying solely on static reviews conducted annually.

Least-privilege access controls remain foundational. Organizations are reducing broad persistent vendor access in favor of narrower, purpose-built permissions that can be adjusted or revoked quickly as conditions change.

“Every time a vendor connects, their identity should be verified, and their access should be limited to exactly what they need and nothing more,” Schiappa says. 

DIVE DEEPER: Find out how to manage the convergence of IT and operational technology securely.

Using SBOMs to Expose Hidden Software Dependencies

Software Bills of Materials, or SBOMs, have become an important tool for understanding hidden dependencies buried inside enterprise software stacks.

They provide machine-readable inventories of software components, libraries and dependencies, allowing organizations to identify exposure more quickly when new vulnerabilities emerge.

“Teams can quickly see whether they are affected and where, rather than scrambling to find out,” Schiappa says. 

The technology also helps expose fourth-party dependencies that organizations may not realize exist within vendor products themselves.

However, maintaining accurate SBOMs remains operationally difficult. Dependencies change constantly, and stale inventories can create false confidence instead of meaningful visibility.

“Building the SBOM is actually the easier half,” Zugec notes. “Maintaining one as a living, operationally useful artifact requires ongoing investment.” 

DISCOVER: Is your organization ready to adopt continuous threat exposure management?

Implementing Zero Trust and Continuous Monitoring Across Vendor Ecosystems

Many organizations now view supply chain security through the lens of zero-trust architecture.

The approach extends beyond simply verifying user identity at login. Security teams are increasingly applying zero-trust principles directly to vendor integrations, APIs, workloads and software execution itself.

Winston says supply chain attacks have made traditional assumption of a trusted internal network obsolete.

“There is no trusted interior anymore,” he explains.

Continuous behavioral monitoring has become particularly important as attackers increasingly abuse legitimate credentials, signed binaries and approved vendor tools.

Instead of relying entirely on signatures or known indicators of compromise, organizations are monitoring runtime behavior itself for deviations from established baselines.

“Detecting them requires behavioral visibility at the execution layer,” Zugec says.