Thinfinity VirtualUI User Enumeration

mediumseverity

5.3CVSS score

23%likelihood of exploitation, next 30 days

98%of all CVEs are less likely

Readycheck to confirm it

Thinfinity VirtualUI (before v3.0), /changePassword returns different responses for requests depending on whether the username exists. It may enumerate OS users (Administrator, Guest, etc.)

Impact

An attacker can use the gathered usernames for further attacks, such as brute-forcing passwords or launching targeted phishing campaigns.

Fix

Apply the vendor-supplied patch or upgrade to the latest version of Thinfinity VirtualUI to mitigate the user enumeration vulnerability.

How to confirm it

Send: GET /changePassword?username=administrator
Positive when: matches /"rc":(.*?)/ AND status 200

Run it with nuclei: nuclei -id CVE-2021-44848 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-44848

info:
  name: Thinfinity VirtualUI User Enumeration
  author: danielmofer
  severity: medium
  description: Thinfinity VirtualUI (before v3.0), /changePassword returns different responses for requests depending on whether the username exists. It may enumerate OS users (Administrator, Guest, etc.)
  impact: |
    An attacker can use the gathered usernames for further attacks, such as brute-forcing passwords or launching targeted phishing campaigns.
  remediation: |
    Apply the vendor-supplied patch or upgrade to the latest version of Thinfinity VirtualUI to mitigate the user enumeration vulnerability.
  reference:
    - https://github.com/cybelesoft/virtualui/issues/1
    - https://nvd.nist.gov/vuln/detail/CVE-2021-44848
    - https://www.tenable.com/cve/CVE-2021-44848
    - http://packetstormsecurity.com/files/165327/Cibele-Thinfinity-VirtualUI-2.5.41.0-User-Enumeration.html
    - https://github.com/ARPSyndicate/cvemon
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
    cvss-score: 5.3
    cve-id: CVE-2021-44848
    cwe-id: CWE-203
    epss-score: 0.22966
    epss-percentile: 0.97763
    cpe: cpe:2.3:a:cybelesoft:thinfinity_virtualui:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: cybelesoft
    product: thinfinity_virtualui
    shodan-query: http.title:"thinfinity virtualui"
    fofa-query: title="thinfinity virtualui"
    google-query: intitle:"thinfinity virtualui"
  tags: cve2021,cve,exposure,thinfinity,packetstorm,virtualui,tenable,cybelesoft,vuln

http:
  - raw:
      - |
        GET /changePassword?username=administrator HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - '"rc":(.*?)'
          - '"msg":"(.*?)"'
        condition: and

      - type: status
        status:
          - 200

References

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