CVE-2021-4443
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 · uneditedThe WordPress Mega Menu plugin for WordPress is vulnerable to Arbitrary File Creation in versions up to, and including, 2.0.6 via the compiler_save AJAX action. This makes it possible for unauthenticated attackers to create arbitrary PHP files that can be used to execute malicious code.
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 · high confidenceThe WordPress Mega Menu plugin versions up to 2.0.6 contains an arbitrary file creation vulnerability in the compiler_save AJAX action. Unauthenticated attackers can exploit this to create arbitrary PHP files on the server, enabling remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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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Confirm Mega Menu plugin is installedNavigate to WordPress admin dashboard > Plugins, or inspect the wp-content/plugins/mega-menu-lite directoryAffected if The plugin is present in the plugins list or directory
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Determine installed plugin versionCheck the plugin header in mega-menu-lite/mega-menu.php for the Version field, or look at the plugin's main file in the WordPress plugins directoryAffected if The version number is 2.0.6 or lower (any version up to and including 2.0.6 is affected)
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Verify the compiler_save AJAX endpoint is exposedCheck if the WordPress site responds to wp-admin/admin-ajax.php?action=compiler_save (no authentication required for this action in vulnerable versions)Affected if The endpoint returns a response rather than a 401/403 error, indicating it is accessible to unauthenticated users
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Inspect for suspicious PHP files in upload directoriesSearch wp-content/uploads/ and subdirectories for recently created .php files that were not intentionally uploadedAffected if Unexpected PHP files exist, especially in upload directories or the mega-menu plugin folder, which may indicate exploitation
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Review server access logs for compiler_save activitySearch HTTP access logs for requests to admin-ajax.php with action=compiler_save, especially from unexpected IP addressesAffected if Logs show unauthorized POST requests to the compiler_save action, confirming attempted or successful exploitation
A user is affected if the Mega Menu plugin version is 2.0.6 or lower and the compiler_save AJAX endpoint is exposed without authentication.
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.
From vendor dataUpdate the Mega Menu plugin to a version newer than 2.0.6, or remove/deactivate the plugin if no patched version is available.
- Consultation1.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-4443 — 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-2021-4443 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