What’s Vulnerable › Vulnerabilities

CVE-2021-22966

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-11-19 · updated 2026-06-17
• Weakness: CWE-863

Description

Privilege escalation from Editor to Admin using Groups in Concrete CMS versions 8.5.6 and below. If a group is granted "view" permissions on the bulkupdate page, then users in that group can escalate to being an administrator with a specially crafted curl. Fixed by adding a check for group permissions before allowing a group to be moved. Concrete CMS Security team CVSS scoring: 7.1 AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:HCredit for discovery: "Adrian Tiron from FORTBRIDGE ( https://www.fortbridge.co.uk/ )"This fix is also in Concrete version 9.0.0

Affected products

• Concrete CMS: before 8.5.7 — fixed in 8.5.7

How to fix

Upgrade to a fixed version: Concrete CMS 8.5.7. Check the vendor advisory for mitigations.

References

• https://documentation.concretecms.org/developers/introduction/version-history/857-release-notes
• https://hackerone.com/reports/1362747
• https://documentation.concretecms.org/developers/introduction/version-history/857-release-notes
• https://hackerone.com/reports/1362747

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