WS_FTP Server - Insecure Deserialization

Exploited in the wild. Listed by CISA on 2023-10-05; known to be used by ransomware.

criticalseverity

10CVSS score

90.4%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.

Impact

Unauthenticated attackers can exploit .NET deserialization vulnerability in the Ad Hoc Transfer module to execute arbitrary commands on the WS_FTP Server, potentially compromising the entire file transfer infrastructure and accessing all transferred files.

Fix

Update Progress WS_FTP Server to version 8.7.4 or 8.8.2 or later that properly validates deserialization input in the Ad Hoc Transfer module.

How to confirm it

Send: GET {{BaseURL}}/AHT/AHT_UI/public/js/app.min.js
Positive when: matches //\*! fileTransfer \d+-(0[1-9]|1[0-2])-(19\d{2}|20[01]\d|202[0-2]) \*// AND status 200

Run it with nuclei: nuclei -id CVE-2023-40044 -u <target>

The full check

id: CVE-2023-40044

info:
  name: WS_FTP Server - Insecure Deserialization
  author: 0x_Akoko
  severity: critical
  description: |
    In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.
  impact: |
    Unauthenticated attackers can exploit .NET deserialization vulnerability in the Ad Hoc Transfer module to execute arbitrary commands on the WS_FTP Server, potentially compromising the entire file transfer infrastructure and accessing all transferred files.
  remediation: |
    Update Progress WS_FTP Server to version 8.7.4 or 8.8.2 or later that properly validates deserialization input in the Ad Hoc Transfer module.
  reference:
    - https://attackerkb.com/topics/bn32f9sNax/cve-2023-40044
    - https://censys.com/cve-2023-40044/
    - https://www.progress.com/ws_ftp
    - https://www.rapid7.com/blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/
    - https://www.theregister.com/2023/10/02/ws_ftp_update/
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    cvss-score: 10
    cve-id: CVE-2023-40044
    cwe-id: CWE-502
    epss-score: 0.90355
    epss-percentile: 0.99801
    cpe: cpe:2.3:a:progress:ws_ftp_server:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    shodan-query: title:"Ad Hoc Transfer"
    max-request: 1
    vendor: progress
    product: ws_ftp_server
  tags: cve,cve2023,ws_ftp,kev,passive,vkev,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/AHT/AHT_UI/public/js/app.min.js"

    matchers-condition: and
    matchers:
      - type: regex
        part: body
        regex:
          - '/\*! fileTransfer \d+-(0[1-9]|1[0-2])-(19\d{2}|20[01]\d|202[0-2]) \*/'
          - '/\*! fileTransfer \d+-(0[1-8])-2023 \*/'
        condition: or

      - type: status
        status:
          - 200

    extractors:
      - type: regex
        part: body
        regex:
          - '\d+-(0[1-9]|1[0-2])-(19\d{2}|20[01]\d|202[0-2])'
          - '\d+-(0[1-8])-2023'

References

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