CVE-2025-26521 is a vulnerability classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) affecting Apache CloudStack, specifically versions 4.17.0.0 to 4.20.0.0. The issue arises when a user-account creates a CKS-based Kubernetes cluster within a project: the API key and secret key of the 'kubeadmin' user associated with the creator's account are embedded into the Kubernetes cluster's secret configuration. Because project members who have access to the Kubernetes cluster can retrieve this secret, they gain access to the creator's API credentials. This exposure enables an attacker with project membership to impersonate the cluster creator, allowing them to perform privileged operations that can compromise the confidentiality, integrity, and availability of the creator's cloud resources. The vulnerability does not require user interaction but does require the attacker to have project membership and access to the Kubernetes cluster. Apache has addressed this issue in versions 4.19.3.0 and 4.20.1.0 by recommending the use of dedicated service accounts with limited permissions for Kubernetes cluster operations. The mitigation process involves creating a new service account with the 'Project Kubernetes Service Role', adding it to the project, generating new API and secret keys for this account, updating the Kubernetes cluster secret to use these credentials, and regenerating the original user's API keys to invalidate the exposed credentials. This approach limits the scope of credentials exposed within the Kubernetes cluster and reduces the risk of privilege escalation or lateral movement within the cloud environment.

The vulnerability allows unauthorized project members to access sensitive API credentials of the cluster creator, enabling them to impersonate the creator and perform privileged actions. This can lead to a complete compromise of the confidentiality, integrity, and availability of cloud resources owned by the creator's account. Potential impacts include unauthorized data access or exfiltration, modification or deletion of cloud resources, disruption of services, and lateral movement within the cloud infrastructure. Organizations using affected versions of Apache CloudStack in multi-tenant or collaborative project environments face significant risks, especially if project membership is not tightly controlled. The ease of exploitation is moderate since the attacker must have project membership and Kubernetes cluster access, but no user interaction is required. The scope is limited to projects using CKS-based Kubernetes clusters within the affected CloudStack versions, but given CloudStack's use in private and public clouds, the impact can be substantial in environments with multiple users and projects.

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 with the 'Project Kubernetes Service Role' for Kubernetes cluster management, limiting permissions to only what is necessary. 3. Add the service account to the relevant project and generate new API and secret keys for it. 4. Update the Kubernetes cluster secret to use the new service account credentials by deleting the existing 'cloudstack-secret' and creating a new one with the updated keys. 5. Regenerate the original user's API and secret keys to invalidate any exposed credentials. 6. Review project membership and Kubernetes cluster access controls to ensure only authorized users have access. 7. Monitor API key usage and audit logs for suspicious activity related to Kubernetes clusters and project resources. 8. Educate administrators and users about the risks of credential exposure within shared projects and enforce the principle of least privilege for all accounts. These steps go beyond generic patching by restructuring credential management and access control to minimize future exposure risks.