Vulnerability in Apache Cloudstack
CVE-2025-66171
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (42.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Apache Cloudstack
- Apache Software Foundation Cloudstack — versions 4.21.0.0
Weakness classification (CWE)
References
- lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm (vendor-advisory, Mailing List, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2025-66171?
- CVE-2025-66171 is a medium-severity vulnerability in Apache Cloudstack, classified under Exposure of Private Personal Information to an Unauthorized Actor. CVSS score: 6.5/10. Published 2026-05-08.
- How severe is CVE-2025-66171?
- Medium severity. CVSS v3 base score is 6.5 out of 10.