Posts Tagged ‘PyTorch’
[DefCon32] DEF CON 32: Grand Theft Actions – Abusing Self-Hosted GitHub Runners
Adnan Khan and John Stawinski, security researchers, delivered a riveting presentation at DEF CON 32, exposing systemic vulnerabilities in GitHub Actions’ self-hosted runners. Their research revealed how misconfigurations enable attackers to compromise major open-source projects like PyTorch, leading to supply chain attacks. Earning over $250,000 in bug bounties, Adnan and John shared tactics, techniques, and procedures (TTPs) to elevate trivial compromises into critical breaches, urging organizations to bolster CI/CD security.
Exploiting Self-Hosted Runner Misconfigurations
Adnan and John opened by explaining GitHub Actions’ role as a leading CI/CD platform and its reliance on self-hosted runners—machines executing workflow jobs. They detailed how insecure defaults allow attackers to compromise runners, gaining access to sensitive repositories. Their attack on PyTorch demonstrated how a runner compromise enabled code contributions to the main branch, malicious release uploads, and backdooring related projects, highlighting the catastrophic potential of such flaws.
Escalating Privileges in GitHub Actions
Delving deeper, the duo showcased techniques to escalate privileges within GitHub Actions workflows, leveraging GitHub’s permissive features. Their research campaign uncovered vulnerabilities in organizations like Microsoft, TensorFlow, and ByteDance, exploiting misconfigured runners to achieve critical impacts. Adnan’s live demo illustrated how attackers could manipulate workflows to gain unauthorized access, emphasizing the need for robust access controls and monitoring in CI/CD pipelines.
Real-World Impact and Bug Bounty Success
Adnan and John shared war stories from their extensive bug bounty submissions, noting that internal CI/CD systems are often more vulnerable than public ones. Their work, yielding significant bounties, exposed a lack of awareness around CI/CD security. They highlighted successful mitigations by triage teams, urging organizations to learn from their findings. The duo’s research on platforms like HackerOne provides a blueprint for identifying similar vulnerabilities in other systems.
Strengthening CI/CD Security
Concluding, Adnan and John emphasized the need for heightened awareness among developers, architects, and executives to prevent supply chain attacks. They recommended isolating privileged runners, auditing configurations, and educating teams on CI/CD risks. Their call to action inspired attendees to explore these attacks and implement controls, ensuring organizations are better equipped to thwart the next critical breach in their CI/CD pipelines.