CVE-2021-25742 : Vulnerability Insights and Analysis

A security issue was discovered in Kubernetes ingress-nginx that allowed a user to retrieve secrets across all namespaces using custom snippets feature.

Understanding CVE-2021-25742

This CVE refers to a vulnerability in Kubernetes ingress-nginx that enables unauthorized access to secrets in the cluster.

What is CVE-2021-25742?

CVE-2021-25742 is a security flaw in ingress-nginx that allows a user to exploit custom snippets to obtain all secrets in the cluster.

The Impact of CVE-2021-25742

The vulnerability has a CVSS base score of 7.6, making it high severity with a significant impact on confidentiality.

Technical Details of CVE-2021-25742

The vulnerability allows a user to use custom snippets to access secrets in the Kubernetes ingress-nginx service across all namespaces.

Vulnerability Description

The flaw permits users to retrieve all secrets by creating or updating ingress objects and leveraging custom snippets.

Affected Systems and Versions

Versions less than or equal to 0.49.0 and 1.0.0 of Kubernetes ingress-nginx are impacted by this vulnerability.

Exploitation Mechanism

Attackers with access to ingress objects can exploit the custom snippets feature to extract sensitive information from the cluster.

Mitigation and Prevention

To address CVE-2021-25742, disallow snippet annotations on supported versions. Visit the Kubernetes ingress-nginx GitHub page for detailed mitigation instructions.

Immediate Steps to Take

Disable the use of snippet annotations on affected versions and implement access controls to prevent unauthorized retrieval of secrets.

Long-Term Security Practices

Regularly update to patched versions of ingress-nginx and monitor for any abnormal activities related to secrets access.

Patching and Updates

Keep Kubernetes ingress-nginx up to date with the latest security patches and follow best practices for securing secrets.