CI/CD Pipeline Flaws Expose Supply Chains to Unauthenticated Attacks

Novee Security released research revealing a CI/CD vulnerability pattern dubbed "Cordyceps" that could allow anyone with a free, unauthenticated GitHub account to take over trusted build workflows and infiltrate open-source software chains. The flaw surfaced across major organizations including Microsoft, Google, Apache, Python, and Cloudflare.

After examining roughly 30,000 high-impact repositories, researchers flagged 654 as potentially vulnerable and confirmed 300 as fully compromised—a stark reminder that the continuous integration and continuous deployment pipeline has become a prime attack vector.

Why Workflow Vulnerabilities Slip Past Code Review#

The gap between what security teams catch and what attackers exploit comes down to how organizations treat CI/CD configuration. According to Elad Meged, a founding engineer at Novee Security, most teams view workflow YAML files as mere configuration rather than security-critical code. In reality, these files execute commands, manage credentials, publish packages, and orchestrate release decisions—meaning a single flaw can be just as dangerous as a vulnerability in application code itself.

Conventional code review processes focus on whether workflows perform their intended functions—building, testing, and deploying correctly. However, reviewers typically fail to ask the harder security questions: Who has permission to trigger the workflow? What system privileges does it receive? Are secrets exposed? Can data from external pull requests influence a privileged operation?

Security scanners compound the problem. Rather than understanding workflow context and tracking how untrusted data flows through elevated operations, most scanners simply hunt for known-bad patterns—specific strings or settings. A vulnerability like Cordyceps doesn't fit that mold; instead, it represents a subtle pathway where low-privilege external input reaches a high-privilege action, a distinction that requires deeper contextual reasoning to detect.

Reframing CI/CD as Core Supply Chain Infrastructure#

Recent incidents underscore that the pipeline is no longer peripheral infrastructure. In March, a threat actor group exploited Aqua Security's own Trivy vulnerability scanner as part of a broader supply chain attack targeting millions of developers. The Cordyceps discovery follows a similar pattern—attackers targeting the build chain itself.

Security researcher Peyton Kennedy notes the scale of potential damage: "The damage from a single mistake tends to be large since pipelines hold the keys to source code, secrets, and the ability to ship software, so one foothold can reach far downstream."