CVE-2021-22966 — concrete5/core
HIGHCVE-2021-22966 is a high-severity (CVSS 8.8) CWE-863 vulnerability in concrete5/core. A fix is available for concrete5/core — see the affected versions and patch details below.
Improper Privilege Management in Concrete CMS
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2021-22966 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
concrete5/coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | concrete5/core | all versions | 8.5.7composer require concrete5/core:^8.5.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for concrete5/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update concrete5/core to 8.5.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-22966 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2021-22966 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-22966. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2021-22966 in your dependencies?
O3 Security finds CVE-2021-22966 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.