CVE-2016-3738 in OpenShift Enterprise
Summary
by MITRE
Red Hat OpenShift Enterprise 3.2 does not properly restrict access to STI builds, which allows remote authenticated users to access the Docker socket and gain privileges via vectors related to build-pod.
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Analysis
by VulDB Data Team • 08/23/2022
The vulnerability identified as CVE-2016-3738 affects Red Hat OpenShift Enterprise 3.2 and represents a critical access control flaw that undermines the security boundaries of containerized applications. This issue stems from improper restrictions within the Source-to-Image (STI) build process, which is a fundamental component of OpenShift's application deployment pipeline. The vulnerability specifically targets the build-pod mechanism that orchestrates container image creation from source code, creating a pathway for authenticated attackers to escalate their privileges within the cluster environment.
The technical flaw manifests when STI builds are executed without adequate isolation of the build process from the underlying host system. Attackers with legitimate authentication credentials can exploit this weakness to gain unauthorized access to the Docker socket that runs on the build pod. This socket provides low-level access to the Docker daemon, enabling malicious actors to execute privileged operations such as creating new containers, accessing host filesystems, and potentially compromising other workloads running on the same node. The vulnerability exists because the build-pod configuration fails to properly sandbox the container build process, allowing the build environment to inherit elevated privileges that should be restricted.
From an operational impact perspective, this vulnerability creates a significant risk for organizations using OpenShift Enterprise 3.2 as their container orchestration platform. An authenticated attacker who gains access to the build process can effectively bypass the multi-tenant security model that OpenShift is designed to provide. The access to the Docker socket enables privilege escalation attacks that could lead to complete compromise of the node where the build pod executes, potentially allowing attackers to move laterally across the cluster. This vulnerability directly impacts the principle of least privilege and undermines the security posture of containerized applications, particularly in multi-tenant environments where isolation between different users and applications is critical.
The vulnerability aligns with CWE-276, which addresses improper privilege management, and demonstrates characteristics consistent with ATT&CK technique T1059.001 for command and scripting interpreter execution. Organizations should implement immediate mitigations including upgrading to patched versions of OpenShift Enterprise 3.2, implementing network segmentation to limit access to build pods, and configuring proper RBAC policies to restrict who can initiate STI builds. Additionally, monitoring for unauthorized access to Docker socket endpoints and implementing container runtime security controls can help detect exploitation attempts. The security community should also consider the broader implications for container orchestration platforms and ensure that build processes are properly isolated from host-level privileges to prevent similar vulnerabilities in other container management systems.