MoodleCMS
CVE-2024-38274
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedInsufficient escaping of calendar event titles resulted in a stored XSS risk in the event deletion prompt.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA stored XSS vulnerability exists where calendar event titles are not properly escaped when displayed in the event deletion prompt. An attacker can craft a malicious event title containing JavaScript code that executes when an administrator or user views the deletion confirmation dialog.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
MoodleCMS
>= 4.1.0, < 4.1.11>= 4.2.0, < 4.2.8>= 4.3.0, < 4.3.5= 4.4.0
FedoraOperating system
= 39= 40CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Moodle versionNavigate to Site administration > Server > Environment or check the version.php file in the Moodle root directory (typically /lib/version.php). Look for the $release or $version variable.Affected if The installed version falls within: 4.1.0 to 4.1.10, 4.2.0 to 4.2.7, 4.3.0 to 4.3.4, or 4.4.0 (any patch level).
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Confirm calendar module is enabledGo to Site administration > Plugins > Activity modules and verify the 'Calendar' module (mod_calendar) is installed and enabled.Affected if Calendar module is enabled and users can create calendar events.
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Identify calendar event titles in the databaseQuery the Moodle database: SELECT id, name, course, userid FROM mdl_event WHERE name LIKE '%<script%' OR name LIKE '%javascript:%' OR name LIKE '%onload=%' OR name LIKE '%onerror=%'. This searches for common XSS patterns in event titles.Affected if Any calendar events exist with names containing HTML/JavaScript code such as <script>, javascript:, onload=, onerror=, or other XSS vectors.
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Test deletion prompt renderingAs an administrator or user with calendar event deletion permissions, create a test calendar event with a title containing HTML characters (e.g., <img src=x onerror=alert(1)>), then attempt to delete it and inspect the deletion confirmation prompt in the browser developer tools (View Page Source).Affected if The event title is rendered unescaped in the deletion confirmation dialog, executing any embedded JavaScript.
You are affected if running a vulnerable Moodle version AND the calendar module is enabled AND malicious or unescaped event titles exist in the system, causing code execution when deletion prompts are viewed.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.1.114.2.84.3.5
Implement proper output encoding/escaping for calendar event titles in all user-facing contexts, particularly the deletion prompt. Use context-appropriate encoding (HTML encoding for HTML contexts).
Moodle 4.1.11, 4.2.8, 4.3.5, or 4.4.1 (choose the version matching your release train)
- 1. Back up your Moodle database and codebase before performing any upgrade
- 2. Download the appropriate fixed Moodle version for your current installation: 4.1.11, 4.2.8, 4.3.5, or 4.4.1
- 3. Replace your current Moodle files with the files from the fixed version, preserving your config.php and any custom themes or plugins
- 4. Run the Moodle upgrade script by accessing your Moodle site in a web browser
- 5. Clear all Moodle caches after upgrade completion
- 6. Verify that calendar event deletion prompts properly escape special characters in event titles
- 7. If using Fedora's packaged Moodle, update via: dnf update moodle (once Fedora packages are updated to the fixed versions)
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Moodle
Scoped from the published advisory
- Consultation3.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-38274 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-38274 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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