Security researchers at Tenable have uncovered a significant vulnerability in Google Cloud Run that could potentially allow malicious actors to gain unauthorized access to private containers and inject harmful code. The vulnerability, dubbed ImageRunner, was successfully patched by Google on January 28, 2025, following responsible disclosure protocols.
Understanding the ImageRunner Vulnerability
The vulnerability stemmed from insufficient access control validation within Google Cloud Run’s revision management system. Attackers with run.services.update and iam.serviceAccounts.actAs permissions could potentially exploit this flaw to access private container images stored in both Google Artifact Registry and Container Registry. This security oversight created a significant risk for organizations leveraging Google’s containerized application services.
Technical Impact and Attack Vector Analysis
The exploitation methodology revealed a concerning weakness in the cloud service’s architecture. Malicious actors could potentially manipulate Cloud Run service configurations to bypass intended access controls, leading to unauthorized access to private container repositories. This vulnerability exemplifies the complex security challenges in modern cloud infrastructures, where interconnected services can create unexpected attack vectors.
Security Implications for Cloud Infrastructure
The discovery highlights what security experts term the “Jenga effect” in cloud computing environments, where the interdependency of services can lead to cascading security vulnerabilities. The potential impact of ImageRunner included:
– Unauthorized access to proprietary container images
– Malicious code injection capabilities
– Extraction of sensitive data and credentials
– Potential establishment of persistent access through reverse shells
Google’s Security Response and Remediation
Google’s security team implemented comprehensive fixes to address the vulnerability. The enhanced security measures now enforce explicit container image access permissions for all users and service accounts performing create or update operations in Cloud Run. This implementation significantly strengthens the service’s security posture and helps prevent unauthorized access attempts.
This security incident serves as a crucial reminder of the importance of implementing robust access control mechanisms in cloud environments. Organizations utilizing Google Cloud Platform should conduct regular security audits, implement principle of least privilege access controls, and maintain up-to-date security policies. The incident also emphasizes the critical need for continuous monitoring and security assessment of cloud infrastructure to protect against emerging threats and vulnerabilities.
