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CloudstackApplication · Apache

CVE-2025-66171

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-08
Fix available
A fix is available. Upgrade to 4.22.0.1 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The CloudStack Backup plugin has an improper access logic in versions 4.21.0.0 and 4.22.0.0. Anyone with authenticated user-account access in CloudStack 4.21.0.0+ environments, where this plugin is enabled and have access to specific APIs can create new VMs using backups of any other user of the environment. Backup plugin users using CloudStack 4.21.0.0+ are recommended to upgrade to CloudStack version 4.22.0.1, which fixes this issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The CloudStack Backup plugin in versions 4.21.0.0 and 4.22.0.0 has improper access control logic that allows any authenticated user to create new VMs using backups belonging to other users in the environment. This authorization bypass occurs when the plugin is enabled and users have access to specific restore/create-from-backup APIs.

MitigationUpgrade CloudStack to version 4.22.0.1 which contains the fix for this improper access control vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
CloudstackApplication
Affected:>= 4.21.0.0, < 4.22.0.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify your Apache CloudStack version
    Locate the installed CloudStack version through the management server or admin interface, typically accessible via the UI footer or management server logs
    Affected if The installed version is >= 4.21.0.0 and < 4.22.0.1
  2. Verify the Backup plugin status
    Check whether the CloudStack Backup plugin is enabled in your environment through the plugin management interface or configuration
    Affected if The Backup plugin is enabled and active in the environment
  3. Inspect API access controls for backup restore APIs
    Review the API access permissions configuration to determine which users can access the restore/create-from-backup API endpoints
    Affected if Authenticated users without proper tenant isolation can access APIs to create VMs from backups belonging to other users or accounts

You are affected if your CloudStack version is between 4.21.0.0 and 4.22.0.1 inclusive AND the Backup plugin is enabled, allowing unauthorized cross-user VM creation from backups.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.22.0.1 or later
Fixed in 4.22.0.1
Interim mitigation

Upgrade CloudStack to version 4.22.0.1 which contains the fix for this improper access control vulnerability.

Recommended fix High confidence

CloudStack 4.22.0.1

  1. Backup the existing CloudStack database and configuration files
  2. Stop all CloudStack services (management server, agents)
  3. Download CloudStack version 4.22.0.1 from the official Apache CloudStack repository
  4. Upgrade the CloudStack management server packages to version 4.22.0.1
  5. Run any database migration scripts included in the upgrade (e.g., 'cloudstack-setup-databases' or similar upgrade tooling)
  6. Restart the CloudStack management server and agent services
  7. Verify that the Backup plugin is functioning correctly post-upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Cloudstack Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-66171 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data