CVE-2019-11247 : Vulnerability Insights and Analysis
Learn about CVE-2019-11247 where Kubernetes kube-apiserver allows unauthorized access to cluster-scoped resources. Find out the impacted versions and mitigation steps.
Kubernetes kube-apiserver mistakenly allows access to a cluster-scoped custom resource if the request is made as if the resource were namespaced. Learn about the impact, technical details, and mitigation steps.
Understanding CVE-2019-11247
The kube-apiserver in Kubernetes has a flaw that grants access to a custom resource scoped to the entire cluster when requested as if limited to a specific namespace.
What is CVE-2019-11247?
The vulnerability allows a user with access to a resource in one namespace to manipulate cluster-scoped resources based on their namespace privileges.
The Impact of CVE-2019-11247
- CVSS Score: 5 (Medium)
- Attack Vector: Network
- Attack Complexity: High
- Privileges Required: Low
- Confidentiality Impact: Low
- Integrity Impact: Low
- Availability Impact: Low
Technical Details of CVE-2019-11247
Vulnerability Description
The kube-apiserver in Kubernetes incorrectly enforces authorizations for custom resources, leading to unauthorized access.
Affected Systems and Versions
- Kubernetes versions prior to 1.13.9, 1.14.5, 1.15.2, 1.7, 1.8, 1.9, 1.10, 1.11, 1.12
Exploitation Mechanism
The flaw allows users to manipulate cluster-scoped resources by exploiting namespace-specific privileges.
Mitigation and Prevention
Immediate Steps to Take
- Remove authorization rules granting access to cluster-scoped resources within namespaces
- Review and adjust RBAC roles and clusterroles
Long-Term Security Practices
- Regularly review and update access control policies
- Conduct security audits to identify similar vulnerabilities
Patching and Updates
- Update Kubernetes to versions 1.13.9, 1.14.5, 1.15.2 or newer to address the vulnerability