CVE-2021-29452 — @curveball/a12n-server
MEDIUMCVE-2021-29452 is a medium-severity (CVSS 6.5) Improper Privilege Management vulnerability in @curveball/a12n-server. A fix is available for @curveball/a12n-server — see the affected versions and patch details below.
Any logged in user could edit any other logged in user.
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-2021-29452 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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@curveball/a12n-servernpmDescription
a12n-server is an npm package which aims to provide a simple authentication system. A new HAL-Form was added to allow editing users in version 0.18.0. This feature should only have been accessible to admins. Unfortunately, privileges were incorrectly checked allowing any logged in user to make this change. Patched in v0.18.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @curveball/a12n-server | ≥ 0.18.0&&< 0.18.2 | 0.18.2npm install @curveball/a12n-server@0.18.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @curveball/a12n-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @curveball/a12n-server to 0.18.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29452 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-2021-29452 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2021-29452. 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-2021-29452 in your dependencies?
O3 Security finds CVE-2021-29452 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.