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Concrete CmsApplication · Concretecms

CVE-2021-22953

MEDIUM · 5.4 CVSS v3.1 Published 2021-09-23
Fix available
A fix is available. Upgrade to after 8.5.5 or later.
See remediation →
61/100
Remediation priority · Elevated
Remotely reachable No privileges

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
A CSRF in Concrete CMS version 8.5.5 and below allows an attacker to clone topics which can lead to UI inconvenience, and exhaustion of disk space.Credit for discovery: "Solar Security Research Team"

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

A Cross-Site Request Forgery (CSRF) vulnerability in Concrete CMS versions 8.5.5 and below allows unauthenticated attackers to trick authenticated administrators into cloning topics repeatedly. Since topic cloning does not require anti-CSRF tokens, an attacker can craft a malicious page that forces the victim's browser to send cloning requests, potentially creating numerous duplicate topics.

MitigationImplement CSRF token validation on the topic cloning functionality by adding anti-CSRF tokens to forms and validating them server-side, and validate Origin/Referer headers to prevent cross-site requests.

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
Concrete CmsApplication
Affected:<= 8.5.5

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
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

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 Concrete CMS version
    Log into the admin dashboard and navigate to Dashboard > System & Settings > Basics > Maintenance Mode. The version is typically displayed in the admin footer area, or check the file /application/config/app.php for version information.
    Affected if The installed version is 8.5.5 or any version below 8.5.5 (e.g., 8.5.4, 8.5.3, etc.)
  2. Verify topic cloning feature exists
    Navigate to the topic tree manager in the dashboard (Dashboard > Content > Topics) and confirm the cloning functionality is available. Topic cloning is typically accessed via a clone icon or link next to existing topics.
    Affected if The topic cloning feature is present and accessible to authenticated administrators
  3. Inspect topic cloning request for CSRF token
    Use browser developer tools (Network tab) to capture a topic cloning request. Submit a clone action and examine if the request includes a CSRF token parameter (commonly named ccm_token, token, or similar) in either the request body or headers.
    Affected if The cloning request does NOT include a valid CSRF token parameter and relies only on session authentication

You are affected if your Concrete CMS version is 8.5.5 or lower AND the topic cloning form/action lacks CSRF token validation.

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
Upgrade available Upgrade to a release after 8.5.5
Interim mitigation

Implement CSRF token validation on the topic cloning functionality by adding anti-CSRF tokens to forms and validating them server-side, and validate Origin/Referer headers to prevent cross-site requests.

Recommended fix Moderate confidence

Concrete CMS 8.5.6 or later

  1. 1. Back up your Concrete CMS database and files completely before attempting any upgrade
  2. 2. Download Concrete CMS version 8.5.6 or later from the official Concrete CMS marketplace or GitHub repository
  3. 3. Upload the new version files to your server, overwriting the existing installation
  4. 4. Run the concrete/bin/concrete or /index.php/tools/required/upgrade script to apply database migrations
  5. 5. Verify the upgrade was successful by logging into the dashboard and checking the version number
Caveat Minor version upgrades in the 8.x branch are typically safe; always test in staging first and backup your site

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

Fix this in Concrete Cms Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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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-2021-22953 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