CVE-2019-11250 : What You Need to Know

Kubernetes client-go logs authorization headers at debug verbosity levels.

Understanding CVE-2019-11250

The logging feature in the Kubernetes client-go library can potentially expose credentials to unauthorized individuals through logs or command output when verbosity levels of 7 or higher are used.

What is CVE-2019-11250?

The issue affects Kubernetes components, like kube-apiserver, that utilize basic or bearer token authentication and run at high verbosity levels, but this problem has been addressed in versions prior to v1.16.0.

The Impact of CVE-2019-11250

CVSS Score: 4.7 (Medium)
Confidentiality Impact: High
Attack Complexity: High
Attack Vector: Local
Unauthorized disclosure of credentials through logs or command output.

Technical Details of CVE-2019-11250

The following technical details provide insight into the vulnerability.

Vulnerability Description

The Kubernetes client-go library logs request headers at verbosity levels of 7 or higher, potentially exposing credentials to unauthorized users.

Affected Systems and Versions

Affected Product: Kubernetes
Affected Versions: Prior to 1.16.0

Exploitation Mechanism

The issue occurs when Kubernetes components, such as kube-apiserver, use basic or bearer token authentication and operate at high verbosity levels.

Mitigation and Prevention

Steps to address and prevent the vulnerability.

Immediate Steps to Take

Lower log verbosity levels to 6 or below to mitigate the risk of exposing credentials.

Long-Term Security Practices

Regularly review and adjust logging levels to minimize sensitive information exposure.
Implement least privilege access controls to limit unauthorized access to sensitive data.
Stay informed about security updates and patches for Kubernetes.
Educate users on secure logging practices.

Patching and Updates

Ensure that Kubernetes is updated to version 1.16.0 or higher to address the vulnerability.