CyberSecBulletin
CVE-2025-26521NVD status: Analyzed

Apache CloudStack: Exposure of Sensitive Information to an Unauthorized Actor

Published Updated By the CyberSecBulletin desk

CVE-2025-26521 is a high-severity exposure of sensitive information to an unauthorized actor vulnerability in Apache CloudStack from Apache, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 4.19.3.0, 4.20.1.0 as the first without the flaw, so updating Apache CloudStack to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.71% chance of exploitation within 30 days, higher than 54% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Apache CloudStack to 4.19.3.0 or 4.20.1.0, whichever matches your release line, or a later version.
  2. Update Cloudstack to 4.19.3.0 or 4.20.1.0, whichever matches your release line, or a later version.
  3. Read the advisory on cloudstack.apache.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
ApacheApache CloudStack4.17.0.0 up to, but not including, 4.19.3.0; 4.20.0.0 up to, but not including, 4.20.1.04.19.3.0, 4.20.1.0
ApacheCloudstack4.17.0.0 up to, but not including, 4.19.3.0; 4.20.0.0 up to, but not including, 4.20.1.04.19.3.0, 4.20.1.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CISA (ADP).

Official description

When an Apache CloudStack user-account creates a CKS-based Kubernetes cluster in a project, the API key and the secret key of the 'kubeadmin' user of the caller account are used to create the secret config in the CKS-based Kubernetes cluster. A member of the project who can access the CKS-based Kubernetes cluster, can also access the API key and secret key of the 'kubeadmin' user of the CKS cluster's creator's account. An attacker who's a member of the project can exploit this to impersonate and perform privileged actions that can result in complete compromise of the confidentiality, integrity, and availability of resources owned by the creator's account. CKS users are recommended to upgrade to version 4.19.3.0 or 4.20.1.0, which fixes this issue.Updating Existing Kubernetes Clusters in ProjectsA service account should be created for each project to provide limited access specifically for Kubernetes cluster providers and autoscaling. Follow the steps below to create a new service account, update the secret inside the cluster, and regenerate existing API and service keys:1. Create a New Service AccountCreate a new account using the role "Project Kubernetes Service Role" with the following details: Account Name kubeadmin-<FIRST_EIGHT_CHARACTERS_OF_PROJECT_ID> First Name Kubernetes Last Name Service User Account Type 0 (Normal User) Role ID <ID_OF_SERVICE_ROLE> 2. Add the Service Account to the ProjectAdd this account to the project where the Kubernetes cluster(s) are hosted. 3. Generate API and Secret KeysGenerate API Key and Secret Key for the default user of this account. 4. Update the CloudStack Secret in the Kubernetes ClusterCreate a temporary file `/tmp/cloud-config` with the following data: api-url = <API_URL> # For example: <MS_URL>/client/api api-key = <SERVICE_USER_API_KEY> secret-key = <SERVICE_USER_SECRET_KEY> project-id = <PROJECT_ID> Delete the existing secret using kubectl and Kubernetes cluster config: ./kubectl --kubeconfig kube.conf -n kube-system delete secret cloudstack-secret Create a new secret using kubectl and Kubernetes cluster config: ./kubectl --kubeconfig kube.conf -n kube-system create secret generic cloudstack-secret --from-file=/tmp/cloud-config Remove the temporary file: rm /tmp/cloud-config5. Regenerate API and Secret KeysRegenerate the API and secret keys for the original user account that was used to create the Kubernetes cluster.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities (CWE-200)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Apache CloudStack

All Apache CloudStack vulnerabilities

Recent Exposure of Sensitive Information to an Unauthorized Actor vulnerabilities

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