In a startling revelation, cybersecurity specialists have uncovered two innovative assault methodologies targeting infrastructure-as-code (IaC) and policy-as-code (PaC) utilities such as HashiCorp’s Terraform and Open Policy Agent (OPA). These tactics exploit the inherent intricacies of domain-specific languages (DSLs), enabling adversaries to infiltrate cloud architectures and pilfer sensitive data.
“While these tailored languages are designed to be more robust than conventional programming languages, and indeed exhibit higher resilience, ‘more secure’ is far from synonymous with invulnerable,” Shelly Raban, a senior security researcher at Tenable, elucidated in a detailed report released last week.
OPA, an eminent open-source policy framework, empowers enterprises to enforce uniform policy governance across cloud-native landscapes encompassing microservices, Kubernetes, and CI/CD pipelines. It employs a native query syntax known as Rego, which the OPA mechanism processes to generate actionable policy determinations.
Weaponizing Rego for Cloud Exploitation
Tenable’s newly delineated attack vector hinges on the software supply chain. Threat actors compromise an access credential to introduce a malevolent Rego policy into an OPA environment. During the policy evaluation phase, this malicious payload facilitates nefarious operations—such as credential siphoning—via a built-in Rego function termed http.send.
Even when deployments implement safeguards to restrict http.send, researchers identified an alternative route: the exploitation of net.lookup_ip_addr. This function, though seemingly benign, can be co-opted for data exfiltration through DNS tunneling techniques.
“Organizations should carefully scrutinize or constrain the use of net.lookup_ip_addr in policy definitions, given its potential to surreptitiously enable data exfiltration,” Raban advised.
Terraform’s Exposure to CI/CD Vulnerabilities
Parallel threats emerge within Terraform, a platform that streamlines cloud resource orchestration using its declarative DSL, HashiCorp Configuration Language (HCL). Adversaries can exploit Terraform’s “terraform plan” command, frequently invoked in GitHub workflows tied to pull requests, to execute unvetted modifications. Such unreviewed configurations may introduce malicious data sources into the CI/CD lifecycle.
“This creates a precarious scenario, particularly in public repositories or even private ones compromised by malicious insiders,” the report emphasized. “Pull requests become a conduit for adversarial objectives, with data sources executed during ‘terraform plan’ sessions lowering barriers to exploitation.”
Malicious data sources could range from rogue external data repositories to compromised Terraform modules or DNS sources. Consequently, security teams are urged to validate third-party components, ensuring their provenance from reputable sources.
Proactive Strategies for Risk Mitigation
To counteract these evolving threats, organizations should adopt a multifaceted security posture:
- Granular Access Governance: Enforce role-based access control (RBAC) guided by the principle of least privilege.
- Comprehensive Monitoring: Implement both application-level and cloud-layer logging for real-time oversight and forensic analysis.
- Network Isolation: Restrict application-level network interactions and data accessibility to minimize exposure.
- Code Vetting in CI/CD Pipelines: Disable the automatic execution of unreviewed configurations to thwart potential infiltration attempts.
Additionally, enterprises can leverage IaC security tools such as Terrascan and Checkov to proactively identify vulnerabilities and compliance deviations before deployment, fortifying their cloud ecosystems against emerging threats.
By exposing these blind spots, cybersecurity experts underscore the importance of continuous vigilance and robust defense mechanisms to safeguard cloud platforms from sophisticated, ever-evolving attack vectors.
