PloneApplication

CVE-2021-33508

MEDIUM · 5.4 CVSS v3.1 Published 2021-05-21
Fix available
A fix is available. Upgrade to after 5.2.4 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

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
Plone through 5.2.4 allows XSS via a full name that is mishandled during rendering of the ownership tab of a content item.

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

Plone CMS through version 5.2.4 contains a stored Cross-Site Scripting (XSS) vulnerability where user full names are not properly sanitized when rendered in the ownership tab of content items. An attacker with the ability to set their full name can inject malicious JavaScript that executes when administrators view the ownership information.

MitigationUpdate Plone to version 5.2.5 or later which contains the fix. As a temporary workaround, restrict ability to modify full user profiles or implement input filtering at the web application firewall level.

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
PloneApplication
Affected:<= 5.2.4

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
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/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 checks

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

  1. Identify installed Plone version
    Access the ZMI (Zope Management Interface) at /manage, navigate to the Plone site root, check the plone_version property or use the @@overview-controlpanel view to see the Plone version. Alternatively, check the CHANGES.txt or setup.py in the Plone installation directory.
    Affected if The installed version is 5.2.4 or earlier (any version up to and including 5.2.4).
  2. Verify access to user profile settings
    Log into the Plone site as a standard user and navigate to the user profile settings (typically /@@personal-information or through the user menu). Locate the 'Full Name' field.
    Affected if Users can edit their own full name without administrative restrictions. The vulnerability requires an attacker to set a malicious full name.
  3. Confirm ownership tab is accessible
    Navigate to any content item in the Plone site, access the 'Ownership' tab (typically found in the content item's editing interface under the 'Categorization' or directly as an 'Ownership' tab).
    Affected if The ownership tab is available and displays user full names in the content ownership information section. This is where the XSS payload would execute.

You are affected if your Plone version is 5.2.4 or earlier AND your Plone installation allows users to modify their own full name AND the ownership tab feature is accessible to administrators viewing content ownership information.

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.

From vendor data
Upgrade available Upgrade to a release after 5.2.4
Interim mitigation

Update Plone to version 5.2.5 or later which contains the fix. As a temporary workaround, restrict ability to modify full user profiles or implement input filtering at the web application firewall level.

Fix this in Plone Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,970
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,752.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-33508 — 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-2021-33508 in production — separate from our analysis above.

No notes yet

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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