Testimonial SliderWordPress extension · Web Settler

CVE-2021-36851

MEDIUM · 5.4 CVSS v3.1 Published 2022-04-04
Fix available
A fix is available. Upgrade to after 3.5.8.3 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
Authenticated (editor or higher user role) Cross-Site Scripting (XSS) vulnerability in Web-Settler Testimonial Slider – Free Testimonials Slider Plugin (WordPress plugin) via parameters mpsp_posts_bg_color, mpsp_posts_description_color, mpsp_slide_nav_button_color.

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

Authenticated XSS in WordPress plugin via unsanitized color parameters (mpsp_posts_bg_color, mpsp_posts_description_color, mpsp_slide_nav_button_color) that allow injection of malicious scripts when rendered in the browser.

MitigationImplement proper input sanitization and output escaping for the affected color parameters using WordPress sanitization functions (e.g., sanitize_hex_color) before rendering.

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
Testimonial SliderWordPress extension
Affected:<= 3.5.8.3

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. Verify Web Settler Testimonial Slider is installed
    Check WordPress plugins admin page or inspect plugin directory for 'testimonial-slider' folder
    Affected if Plugin is installed and active
  2. Check installed plugin version
    View plugin version in WordPress plugin list or read version in plugin main PHP file header
    Affected if Version is 3.5.8.3 or lower
  3. Identify color parameter storage location
    Search plugin database options or settings for mpsp_posts_bg_color, mpsp_posts_description_color, mpsp_slide_nav_button_color
    Affected if These color settings exist in plugin configuration
  4. Inspect color output rendering
    Examine plugin templates or shortcode output code where these color values are used in HTML style attributes or inline CSS
    Affected if Values are echoed directly without escaping or sanitization functions
  5. Confirm authenticated access to settings
    Verify if plugin settings are accessible to WordPress users with contributor role or higher via admin panel
    Affected if Authenticated users can modify color parameters without sanitization

User is affected if Web Settler Testimonial Slider version 3.5.8.3 or lower is installed and color parameters are rendered without sanitization/escaping in the browser.

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 3.5.8.3
Interim mitigation

Implement proper input sanitization and output escaping for the affected color parameters using WordPress sanitization functions (e.g., sanitize_hex_color) before rendering.

Fix this in Testimonial Slider Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-36851 — 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-2021-36851 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