Noptin < 1.6.5 - Open Redirect

id: CVE-2021-25033

info:
  name: Noptin < 1.6.5 - Open Redirect
  author: dhiyaneshDk
  severity: medium
  description: Noptin < 1.6.5 is susceptible to an open redirect vulnerability. The plugin does not validate the "to" parameter before redirecting the user to its given value, leading to an open redirect issue.
  impact: |
    An attacker can trick users into visiting malicious websites, leading to phishing attacks.
  remediation: |
    Update to Noptin plugin version 1.6.5 or later.
  reference:
    - https://wpscan.com/vulnerability/c2d2384c-41b9-4aaf-b918-c1cfda58af5c
    - https://plugins.trac.wordpress.org/changeset/2639592
    - https://nvd.nist.gov/vuln/detail/CVE-2021-25033
    - https://github.com/ARPSyndicate/kenzer-templates
  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-2021-25033
    cwe-id: CWE-601
    epss-score: 0.02682
    epss-percentile: 0.84008
    cpe: cpe:2.3:a:noptin:noptin:*:*:*:*:*:wordpress:*:*
  metadata:
    max-request: 1
    vendor: noptin
    product: noptin
    framework: wordpress
  tags: cve2021,cve,wp,wpscan,wordpress,redirect,wp-plugin,noptin,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/?noptin_ns=email_click&to=https://interact.sh"

    matchers:
      - type: regex
        part: header
        regex:
          - '(?m)^(?:Location\s*?:\s*?)(?:https?:\/\/|\/\/|\/\\\\|\/\\)(?:[a-zA-Z0-9\-_\.@]*)interact\.sh\/?(\/|[^.].*)?$' # https://regex101.com/r/L403F0/1
# digest: 4a0a00473045022100d5073b913515a2066dfbc6209b46dc460503ba0bbec2782054db3795891dcf08022003c3ee9dac2ec5fe3cb2d7c6371358dd3e1e2e3556e6778d2b1780a07730a003:922c64590222798bb761d5b6d8e72950