CVE-2025-26521 is a high-severity vulnerability affecting Apache CloudStack versions 4.17.0.0 through 4.20.0.0. The issue arises when a user account creates a CKS-based Kubernetes cluster within a project. During cluster creation, the API key and secret key of the 'kubeadmin' user from the creator's account are embedded into the Kubernetes cluster's secret configuration. This design flaw allows any project member with access to the Kubernetes cluster to retrieve these credentials. Consequently, an attacker who is a project member can impersonate the 'kubeadmin' user, gaining privileged access to perform actions that compromise the confidentiality, integrity, and availability of the creator's account resources. The vulnerability is classified under CWE-200, indicating exposure of sensitive information to unauthorized actors. Exploitation requires network access and privileges as a project member but does not require user interaction. The CVSS v3.1 score is 8.1 (High), reflecting the ease of exploitation and the significant impact on confidentiality and integrity. The Apache Software Foundation has addressed this vulnerability in versions 4.19.3.0 and 4.20.1.0. The recommended mitigation involves upgrading to these patched versions and implementing a more secure service account model. Specifically, a dedicated service account with limited permissions should be created per project to handle Kubernetes cluster operations, replacing the use of the original 'kubeadmin' credentials. This process includes creating the service account with the 'Project Kubernetes Service Role', adding it to the project, generating new API and secret keys, updating the Kubernetes cluster secret configuration with these new credentials, and regenerating the original user's keys to invalidate the compromised credentials. This approach limits credential exposure and reduces the risk of privilege escalation within projects hosting Kubernetes clusters.

For European organizations leveraging Apache CloudStack to manage Kubernetes clusters, this vulnerability poses a significant risk. Unauthorized access to 'kubeadmin' credentials can lead to full compromise of cloud resources, including data breaches, unauthorized modifications, and service disruptions. Given the high confidentiality and integrity impact, sensitive data hosted on affected clusters could be exposed or altered, potentially violating GDPR and other data protection regulations. The availability impact is rated low, but the loss of trust and operational disruption can be substantial. Attackers exploiting this flaw from within a project can pivot laterally, escalating privileges and compromising additional resources. This risk is particularly acute for organizations with multi-tenant projects or collaborative environments where multiple users have project access. The breach of privileged credentials can also facilitate supply chain attacks if Kubernetes clusters are used to deploy critical applications. The vulnerability's exploitation does not require user interaction, increasing the likelihood of automated or stealthy attacks. Consequently, European enterprises must prioritize patching and credential management to maintain compliance and secure cloud operations.

1. Upgrade Apache CloudStack to versions 4.19.3.0 or 4.20.1.0 where the vulnerability is fixed. 2. Implement the recommended service account model: create a dedicated service account per project with the 'Project Kubernetes Service Role' to isolate Kubernetes cluster operations from the original 'kubeadmin' user credentials. 3. Add the new service account to the relevant project and generate unique API and secret keys for it. 4. Update the Kubernetes cluster secret configuration by deleting the existing 'cloudstack-secret' and creating a new secret using the service account credentials, ensuring the original 'kubeadmin' keys are no longer used within the cluster. 5. Regenerate API and secret keys for the original user account to invalidate any potentially compromised credentials. 6. Enforce strict access controls and audit logging on project membership to detect unauthorized access attempts. 7. Regularly review and rotate API keys and secrets to minimize exposure duration. 8. Educate project members on the risks of credential exposure and enforce the principle of least privilege for project roles. 9. Monitor Kubernetes cluster secrets and configurations for unauthorized changes or suspicious access patterns. These steps go beyond generic patching by restructuring credential management and access control to prevent similar exposures in the future.