CVE-2018-20321 Explained : Impact and Mitigation

A problem has been found in Rancher versions 2 through 2.1.5, allowing unauthorized execution of administrative commands with privileged rights on the Kubernetes cluster.

Understanding CVE-2018-20321

What is CVE-2018-20321?

An issue in Rancher versions 2 through 2.1.5 enables any project member with access to the default namespace to mount the netes-default service account in a pod, granting them the ability to execute administrative commands with privileged rights on the Kubernetes cluster.

The Impact of CVE-2018-20321

This vulnerability could lead to unauthorized access and potential misuse of administrative privileges within the Kubernetes cluster, compromising the security and integrity of the system.

Technical Details of CVE-2018-20321

Vulnerability Description

The vulnerability in Rancher versions 2 through 2.1.5 allows any project member with access to the default namespace to mount the netes-default service account in a pod, enabling the execution of administrative commands with privileged rights on the Kubernetes cluster.

Affected Systems and Versions

Rancher versions 2 through 2.1.5

Exploitation Mechanism

Unauthorized users with access to the default namespace can mount the netes-default service account in a pod, granting them the ability to execute administrative commands with privileged rights on the Kubernetes cluster.

Mitigation and Prevention

Immediate Steps to Take

Isolate the default namespace in a separate project to restrict access only to cluster administrators.

Long-Term Security Practices

Regularly review and update access permissions to prevent unauthorized accessorse.

Patching and Updates

Update Rancher to versions 2.1.6 and 2.0.11 to address this vulnerability.