Unrestricted File UploadWeakness · CWE-434

CVE-2021-47965

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

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 · unedited
WordPress Plugin WP Super Edit 2.5.4 and earlier contains an unrestricted file upload vulnerability in the FCKeditor component that allows attackers to upload dangerous file types without validation. Attackers can upload arbitrary files through the filemanager upload endpoint to achieve remote code execution and complete system compromise.

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 confidence

The WP Super Edit plugin versions 2.5.4 and earlier contains an unrestricted file upload vulnerability in its FCKeditor component. The filemanager upload endpoint lacks proper file type validation, allowing attackers to upload arbitrary files including malicious PHP scripts. Successful exploitation enables remote code execution and complete system compromise.

MitigationImmediate mitigation involves disabling or removing the WP Super Edit plugin. Permanent fix requires adding strict file type validation (extension whitelist and MIME type checking), securing upload directories, and potentially replacing the outdated FCKeditor component with a maintained alternative.

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 checks

Work through these to decide whether this CVE applies to you.

  1. Verify WP Super Edit plugin is installed
    Check for the plugin directory at wp-content/plugins/wp-super-edit/ or wp-content/plugins/super-edit/ using file system inspection or WordPress admin plugin list
    Affected if The plugin directory exists in the WordPress plugins folder
  2. Determine installed plugin version
    Locate the main plugin file (wp-super-edit.php or similar) and read the Version header from the plugin comment block, or check readme.txt for the stable tag
    Affected if The version number is 2.5.4 or lower, or if no version is visible and the plugin appears to be the old FCKeditor-based release
  3. Confirm FCKeditor component is present
    Check for the FCKeditor folder or file manager component within the plugin directory, typically at wp-content/plugins/wp-super-edit/fckeditor/ or similar path
    Affected if The fckeditor directory or filemanager component exists within the plugin folder
  4. Check if upload endpoint is accessible
    Attempt to access the filemanager upload script directly via HTTP request to paths such as /wp-content/plugins/wp-super-edit/fckeditor/editor/filemanager/ or test for response headers indicating the endpoint exists and responds
    Affected if The FCKeditor filemanager upload endpoint returns a 200 OK response or processes upload requests (even if authentication is required, the vulnerability lies in lack of file type validation)
  5. Inspect upload directory for suspicious files
    Check the plugin upload directories (typically wp-content/plugins/wp-super-edit/fckeditor/editor/filemanager/upload/ or similar) for recently created .php, .phtml, or other executable files with unusual names
    Affected if Unexpected PHP scripts or other executable files are present in the plugin upload folders, especially if created recently or with random-looking names

A user is affected if the WP Super Edit plugin version is 2.5.4 or earlier AND the FCKeditor filemanager component is present and accessible in their WordPress installation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Immediate mitigation involves disabling or removing the WP Super Edit plugin. Permanent fix requires adding strict file type validation (extension whitelist and MIME type checking), securing upload directories, and potentially replacing the outdated FCKeditor component with a maintained alternative.

Recommended fix High confidence
  1. 1. Remove the WP Super Edit plugin immediately as it is an abandoned plugin with no security updates.
  2. 2. Navigate to WordPress admin dashboard > Plugins > Installed Plugins.
  3. 3. Locate 'WP Super Edit' and click 'Deactivate', then click 'Delete'.
  4. 4. Install an actively maintained alternative editor plugin such as 'TinyMCE Advanced' which is the supported replacement.
  5. 5. If the plugin cannot be removed immediately, disable the FCKeditor filemanager upload endpoint by adding rules to .htaccess or web server config to block access to the upload functionality.
  6. 6. Audit the WordPress installation for any malicious files that may have been uploaded through this vulnerability.
  7. 7. Consider a complete forensic review given the CVSS 9.8 severity indicates likely active exploitation.
Caveat The plugin is abandoned with no official fix; complete removal is required. Transition to TinyMCE Advanced for editor functionality.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,000
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-47965 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-47965 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

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.

What belongs here
  • 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