CVE-2020-8566 Explained : Impact and Mitigation

In Kubernetes clusters using Ceph RBD as a storage provisioner, with logging level of at least 4, Ceph RBD admin secrets can be written to logs. This occurs in kube-controller-manager's logs during provisioning of Ceph RBD persistent claims. This affects versions < 1.19.3, < 1.18.10, < 1.17.13.

Understanding CVE-2020-8566

This CVE highlights a vulnerability in Kubernetes clusters that can expose Ceph RBD admin secrets in logs when the log level is set to 4 or higher.

What is CVE-2020-8566?

CVE-2020-8566 is a security vulnerability in Kubernetes clusters utilizing Ceph RBD as a storage provisioner. It allows Ceph RBD admin secrets to be leaked to logs when the logging level is at least 4.

The Impact of CVE-2020-8566

The exposure of Ceph RBD admin secrets in logs poses a risk of unauthorized access to sensitive information, particularly affecting confidentiality.

Technical Details of CVE-2020-8566

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability allows Ceph RBD admin secrets to be inadvertently exposed in logs during the provisioning of Ceph RBD persistent claims in Kubernetes clusters.

Affected Systems and Versions

Product: Kubernetes
Versions Affected: < 1.19.3, < 1.18.10, < 1.17.13

Exploitation Mechanism

Attack Complexity: High
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality Impact: High
Integrity Impact: None
Availability Impact: None

Mitigation and Prevention

To address CVE-2020-8566, follow these mitigation strategies:

Immediate Steps to Take

Avoid enabling verbose logging in production environments (log level >= 4)
Limit access to logs to authorized personnel only

Long-Term Security Practices

Regularly review and update logging configurations to minimize exposure of sensitive information
Implement access controls to restrict access to logs containing sensitive data

Patching and Updates

Apply patches provided by Kubernetes to fix the vulnerability
Stay informed about security advisories and updates from Kubernetes