MoodleCMS
CVE-2024-33997
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 · uneditedAdditional sanitizing was required when opening the equation editor to prevent a stored XSS risk when editing another user's equation.
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 in the equation editor where insufficient sanitization allows malicious scripts to be embedded when editing another user's equation. When the equation is subsequently viewed or rendered, the malicious payload executes in the context of the victim's browser.
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
< 4.1.10>= 4.2.0, < 4.2.7>= 4.3.0, < 4.3.4CVSS 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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Identify installed Moodle versionAccess the site administration panel, navigate to Server > Environment or check the version.php file in the Moodle root directory. Run: grep -i '$version' version.php | head -5Affected if The installed version falls within < 4.1.10, OR >= 4.2.0 and < 4.2.7, OR >= 4.3.0 and < 4.3.4
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Confirm equation editor is accessibleLog in as a teacher or administrator. Navigate to a course, then to the equation editor feature (Atto or Tiny plugin editor, or the TeX filter). Verify the editor loads in any activity where equations can be inserted.Affected if The equation editor component is installed and accessible to users who can create or edit content
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Check for user-created equations in the databaseQuery the Moodle database: SELECT * FROM mdl_filter WHERE active = 1 AND filter = 'tex' (for TeX filter) or check mdl_editor Atto/Tiny plugin tables for equation content. Examine stored equation data for unsanitized script tags.Affected if User-submitted equations exist in the database that may contain raw script tags, iframe elements, or event handlers in equation content
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Verify equation rendering behaviorCreate a test equation containing a benign payload like <img src=x onerror=alert(1)>. Save and view the page in a different browser session. Inspect the page source to see if the payload is rendered as-is or properly escaped.Affected if The equation content is rendered without sanitization and the payload executes or appears unescaped in the HTML source
A user is affected if they run a vulnerable Moodle version (as per the version ranges) AND the equation editor is active AND user-supplied equations are rendered without proper output encoding.
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 · scoped4.1.104.2.74.3.4
Implement proper output encoding and sanitization for all user-supplied content within the equation editor, particularly when loading equations authored by other users. Validate and sanitize any equation data before rendering.
Moodle 4.1.10, 4.2.7, or 4.3.4 (select the appropriate branch for your deployment)
- 1. Back up your Moodle database and all site files before proceeding
- 2. Place your Moodle site into maintenance mode via Site administration > Server > Maintenance mode
- 3. Download the appropriate fixed Moodle version: 4.1.10, 4.2.7, or 4.3.4 (choose the branch matching your current major version) from download.moodle.org
- 4. Extract the new Moodle files and replace your existing moodle directory, preserving your config.php and any custom code in local/ or theme/ directories
- 5. Clear all cache directories: delete contents of /moodle/cache, /moodle/localcache, and /moodle/temp
- 6. Run the upgrade script by visiting your site URL (e.g., https://yourmoodle.com/admin)
- 7. Follow the on-screen upgrade instructions and wait for completion
- 8. Verify the upgrade was successful by logging in and checking the version in Site administration > Server > Environment
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Moodle
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-33997 — 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-2024-33997 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data