CVE-2025-66170 | Apache CloudStack: Any user can list backups that they should not have access to

The CloudStack Backup plugin has an improper authorization 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 has access to specific APIs can list backups from any account in the environment. This vulnerability does not allow them to see the contents of the backup. Users are recommended to upgrade to version 4.22.0.1, which fixes the issue.

Published: 2026-05-08 Last update: 2026-05-11 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-66170 is rated Low Risk (26.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-66170

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-09 0.01%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-66170

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-66170

GitHub Security Advisory for CVE-2025-66170

GHSA-7p28-jcmx-86m5 · Severity: medium — The CloudStack Backup plugin has an improper authorization logic in versions 4.21.0.0 and 4.22.0...

Affected software / configurations for CVE-2025-66170

Vendor Product Version Raw CPE
apache cloudstack >= 4.21.0.0, < 4.22.0.1 cpe:2.3:a:apache:cloudstack:*:*:*:*:*:*:*:*

References for CVE-2025-66170

URL Tags
https://lists.apache.org/thread/n8mt5b7wkpysstb8w7rr9f02kc5cq2xm Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/05/09/1 Mailing List Third Party Advisory
cvelogic Threat Intelligence