Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🐘 Packagist

CVE-2019-3847

MEDIUM

Moodle XSS Vulnerability

Also known asGHSA-qrcj-6fjw-3h9h
Published
Mar 27, 2019
Updated
Apr 10, 2026
Affected
4 pkgs
Patched
4 / 4
Exploits
2 known

Blast Radius

4 pkgs affected
🐘moodle/moodle🐘moodle/moodle🐘moodle/moodle🐘moodle/moodle

Real-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

A vulnerability was found in moodle before versions 3.6.3, 3.5.5, 3.4.8 and 3.1.17. Users with the "login as other users" capability (such as administrators/managers) can access other users' Dashboards, but the JavaScript those other users may have added to their Dashboard was not being escaped when being viewed by the user logging in on their behalf.

Affected Packages

4 total 4 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistmoodle/moodle3.6.0&&< 3.6.33.6.3
🐘Packagistmoodle/moodle3.5.0&&< 3.5.53.5.5
🐘Packagistmoodle/moodle3.2.0&&< 3.4.83.4.8
🐘Packagistmoodle/moodleall versions3.1.17
Exploits & PoCs
2

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 dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for moodle/moodle. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update moodle/moodle to 3.6.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-3847 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether CVE-2019-3847 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2019-3847. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

A vulnerability was found in moodle before versions 3.6.3, 3.5.5, 3.4.8 and 3.1.17. Users with the "login as other users" capability (such as administrators/managers) can access other users' Dashboards, but the JavaScript those other users may have added to their Dashboard was not being escaped when being viewed by the user logging in on their behalf.
O3 Security · Impact-Aware SCA

Is CVE-2019-3847 in your dependencies?

O3 detects CVE-2019-3847 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.