CVE-2021-25318 : Security Advisory and Response

A Incorrect Permission Assignment for Critical Resource vulnerability in Rancher allows users in the cluster to modify resources they should not have access to.

Understanding CVE-2021-25318

This CVE, titled 'rancher: API group not properly specified when creating Kubernetes RBAC resources,' was published on July 15, 2021.

What is CVE-2021-25318?

The vulnerability in Rancher versions prior to 2.5.9 and 2.4.16 allows unauthorized users to manipulate critical resources in the cluster, leading to potential security breaches and data compromise.

The Impact of CVE-2021-25318

With a CVSS v3.1 base score of 8.8 and a high severity rating, this vulnerability poses a significant threat. Attackers could exploit this issue to gain unauthorized access, compromise confidentiality, integrity, and availability of resources with low privileges required.

Technical Details of CVE-2021-25318

This section provides insights into the vulnerability specifics.

Vulnerability Description

The vulnerability arises due to an Incorrect Permission Assignment for Critical Resource in Rancher, permitting unauthorized access to sensitive resources.

Affected Systems and Versions

Rancher versions before 2.5.9 and 2.4.16 are impacted by this vulnerability, exposing them to potential exploitation.

Exploitation Mechanism

Attackers within the cluster can exploit this vulnerability to manipulate resources they are not authorized to access, compromising the security and integrity of the system.

Mitigation and Prevention

Protect your systems from CVE-2021-25318 by following the recommended steps below.

Immediate Steps to Take

Update Rancher to version 2.5.9 or newer to mitigate the vulnerability.
Restrict user permissions within the cluster and monitor resource activities closely.

Long-Term Security Practices

Implement regular security assessments and audits to identify vulnerabilities.
Educate users on best security practices and the importance of access control.

Patching and Updates

Stay informed about security updates from Rancher and apply patches promptly to address known vulnerabilities.