CVE-2020-14321 is a high-severity (CVSS 8.8) CWE-863 vulnerability in moodle/moodle. 5 public exploit references exist, so weaponization risk is real. A fix is available for moodle/moodle — see the affected versions and patch details below.
Moodle Incorrect Authorization vulnerability
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-2020-14321 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 379,145 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
moodle/moodle🐘moodle/moodle🐘moodle/moodle🐘moodle/moodleReal-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
In Moodle before 3.9.1, 3.8.4, 3.7.7 and 3.5.13, teachers of a course were able to assign themselves the manager role within that course.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | moodle/moodle | ≥ 3.9.0-beta&&< 3.9.1 | 3.9.1composer require moodle/moodle:^3.9.1 |
| 🐘Packagist | moodle/moodle | ≥ 3.8.0-beta&&< 3.8.4 | 3.8.4composer require moodle/moodle:^3.8.4 |
| 🐘Packagist | moodle/moodle | ≥ 3.6.0-beta&&< 3.7.7 | 3.7.7composer require moodle/moodle:^3.7.7 |
| 🐘Packagist | moodle/moodle | all versions | 3.5.13composer require moodle/moodle:^3.5.13 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for moodle/moodle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update moodle/moodle to 3.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-14321 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-2020-14321 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-14321. 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-2020-14321 in your dependencies?
O3 Security finds CVE-2020-14321 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.