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Known Exploited Vulnerability
9.8
CRITICAL CVSS 3.1
CVE-2024-55956
Cleo Multiple Products Unauthenticated File Upload Vulnerability - [Actively Exploited]
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.

INFO

Published Date :

Dec. 13, 2024, 9:15 p.m.

Last Modified :

Oct. 21, 2025, 11:16 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

Cleo Harmony, VLTrader, and LexiCom, which are managed file transfer products, contain an unrestricted file upload vulnerability that could allow an unauthenticated user to import and execute arbitrary bash or PowerShell commands on the host system by leveraging the default settings of the Autorun directory.

Required Action :

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Notes :

https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update-CVE-2024-55956 ; https://nvd.nist.gov/vuln/detail/CVE-2024-55956

Affected Products

The following products are affected by CVE-2024-55956 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Cleo lexicom
2 Cleo harmony
3 Cleo vltrader
: Total Affected Vendor : 1 | Products : 3
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
CVSS 3.1 CRITICAL 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Upgrade Cleo products to address an unauthenticated file upload vulnerability.
  • Upgrade to Cleo Harmony version 5.8.0.24 or later.
  • Upgrade to Cleo LexiCom version 5.8.0.24 or later.
  • Upgrade to Cleo VLTrader version 5.8.0.24 or later.
Public PoC/Exploit Available at Github

CVE-2024-55956 has a 3 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2024-55956.

URL Resource
https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Advisory-CVE-Pending Vendor Advisory
https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update Vendor Advisory
https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild Exploit Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-55956
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-55956 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-55956 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
fl4m3-s/Cleo_Unauth_RCE

Proof of concept to use an arbitrary file write to achieve Remote Code Execution in Cleo Harmony, VLTrader, and LexiCom before 5.8.0.24.

Python

Updated: 9 months, 1 week ago
1 stars 0 fork 0 watcher
Born at : Jan. 14, 2025, 3:32 a.m. This repo has been linked 2 different CVEs too.
Profile Photo
ums91/CISA_BOT

CISA Bot is a GitHub bot that automatically monitors the Cybersecurity and Infrastructure Security Agency (CISA) Known Exploited Vulnerabilities (KEV) Catalog. When new vulnerabilities are published in the KEV, the bot creates GitHub issues in this repository with detailed information about each vulnerability.

Python

Updated: 2 months ago
2 stars 1 fork 1 watcher
Born at : Oct. 29, 2024, 10:19 a.m. This repo has been linked 206 different CVEs too.
Profile Photo
Ostorlab/KEV

Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.

cisa-kev vulnerability 0day cisa exploits

Updated: 3 weeks ago
588 stars 42 fork 42 watcher
Born at : April 19, 2022, 8:58 a.m. This repo has been linked 1290 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-55956 vulnerability anywhere in the article.

  • BleepingComputer
American Airlines subsidiary Envoy confirms Oracle data theft attack

Envoy Air, a regional airline carrier owned by American Airlines, confirms that data was compromised from its Oracle E-Business Suite application after the Clop extortion gang listed American Airlines ... Read more

Published Date: Oct 17, 2025 (1 week, 6 days ago)
  • BleepingComputer
Harvard investigating breach linked to Oracle zero-day exploit

Harvard University is investigating a data breach after the Clop ransomware gang listed the school on its data leak site, saying the alleged breach was likely caused by a recently disclosed zero-day v ... Read more

Published Date: Oct 13, 2025 (2 weeks, 4 days ago)
  • BleepingComputer
Oracle patches EBS zero-day exploited in Clop data theft attacks

Oracle is warning about a critical E-Business Suite zero-day vulnerability tracked as CVE-2025-61882 that allows attackers to perform unauthenticated remote code execution, with the flaw actively expl ... Read more

Published Date: Oct 06, 2025 (3 weeks, 4 days ago)
  • cybereason.com
Addressing the CL0P Extortion Campaign Targeting Oracle E-Business Suite (EBS) Users

Cybereason is continuing to investigate. Check the Cybereason blog for additional updates. Overview and What Cybereason Knows So Far July 2025, Oracle released security updates including 309 patches, ... Read more

Published Date: Oct 05, 2025 (3 weeks, 5 days ago)
  • BleepingComputer
Clop extortion emails claim theft of Oracle E-Business Suite data

Mandiant and Google are tracking a new extortion campaign where executives at multiple companies received emails claiming that sensitive data was stolen from their Oracle E-Business Suite systems Acco ... Read more

Published Date: Oct 02, 2025 (4 weeks, 1 day ago)
  • Help Net Security
AI gives ransomware gangs a deadly upgrade

Ransomware continues to be the major threat to large and medium-sized businesses, with numerous ransomware gangs abusing AI for automation, according to Acronis. Ransomware gangs maintain pressure on ... Read more

Published Date: Aug 22, 2025 (2 months, 1 week ago)
  • cybereason.com
CVE-2025-53770 & CVE-2025-53771: Critical On-Prem SharePoint Vulnerabilities

Cybereason is actively investigating exploitation of these vulnerabilities. Check the Cybereason blog for additional updates. Key Takeaways Two zero-day vulnerabilities discovered in on-premise Micros ... Read more

Published Date: Jul 22, 2025 (3 months, 1 week ago)
  • Cyber Security News
213% Increase in Ransomware Attacks Targeting Organizations With First Quarter of 2025

The first quarter of 2025 has witnessed an unprecedented surge in ransomware attacks, with 2,314 victims listed across 74 unique data leak sites, representing a staggering 213% increase compared to th ... Read more

Published Date: Jul 03, 2025 (3 months, 4 weeks ago)
  • The Hacker News
Google Reports 75 Zero-Days Exploited in 2024 — 44% Targeted Enterprise Security Products

Enterprise Security / Vulnerability Google has revealed that it observed 75 zero-day vulnerabilities exploited in the wild in 2024, down from 98 in 2023. Of the 75 zero-days, 44% of them targeted ente ... Read more

Published Date: Apr 29, 2025 (6 months ago)
  • Google Cloud
Hello 0-Days, My Old Friend: A 2024 Zero-Day Exploitation Analysis

Written by: Casey Charrier, James Sadowski, Clement Lecigne, Vlad Stolyarov Executive Summary Google Threat Intelligence Group (GTIG) tracked 75 zero-day vulnerabilities exploited in the wild in 2024, ... Read more

Published Date: Apr 29, 2025 (6 months ago)
  • The Register
Where it Hertz: Customer data driven off in Cleo attacks

Car hire giant Hertz has confirmed that customer information was stolen during the zero-day data raids on Cleo file transfer products last year. A breach notification was issued on Monday on behalf of ... Read more

Published Date: Apr 15, 2025 (6 months, 2 weeks ago)
  • BleepingComputer
Food giant WK Kellogg discloses data breach linked to Clop ransomware

US food giant WK Kellogg Co is warning employees and vendors that company data was stolen during the 2024 Cleo data theft attacks. Cleo software is a managed file transfer utility that was targeted by ... Read more

Published Date: Apr 07, 2025 (6 months, 3 weeks ago)
  • cybereason.com
CVE-2025-23006: Critical Vulnerability Discovered in SonicWall SMA 1000 Series

Key Takeaways Critical vulnerability discovered in SonicWall’s SMA 1000 series appliances, tracked as CVE-2025-23006. Impacted products include Appliance Management Console (AMC) and Central Managemen ... Read more

Published Date: Jan 24, 2025 (9 months ago)
  • security.nl
Clop-groep claimt zestig slachtoffers via recente aanval op Cleo-software

De criminelen achter de Clop-ransomware claimen via de recente aanval op file sharing software van ontwikkelaar Cleo meer dan zestig slachtoffers te hebben gemaakt. Op de eigen 'Clop Leaks' website he ... Read more

Published Date: Dec 27, 2024 (10 months ago)
  • The Register
Ransomware scum blow holes in Cleo software patches, Cl0p (sort of) claims responsibility

Supply chain integration vendor Cleo has urged its customers to upgrade three of its products after an October security update was circumvented, leading to widespread ransomware attacks that Russia-li ... Read more

Published Date: Dec 16, 2024 (10 months, 2 weeks ago)
  • Hackread - Latest Cybersecurity, Tech, Crypto & Hacking News
Cl0p Ransomware Exploits Cleo Vulnerability, Threatens Data Leaks

SUMMARY Cleo Vulnerability Exploited: The Cl0p ransomware group claims to have exploited a critical vulnerability in Cleo’s managed file transfer software, targeting businesses globally. Data Leak Thr ... Read more

Published Date: Dec 16, 2024 (10 months, 2 weeks ago)
  • security.nl
Shadowserver: bijna duizend kwetsbare Cleo-servers op internet

Op internet zijn bijna duizend servers te vinden die kwetsbare file sharing software van Cleo draaien, waarvan het allergrootste deel in de Verenigde Staten, op afstand gevolgd door Canada. Dat meldt ... Read more

Published Date: Dec 16, 2024 (10 months, 2 weeks ago)
  • security.nl
Clop-ransomware claimt verantwoordelijkheid voor datadiefstal via Cleo-lek

De criminelen achter de Clop-ransomware, die vijf jaar geleden nog systemen van de Universiteit van Maastricht infecteerden, zeggen achter de aanvallen te zitten waarbij misbruik wordt gemaakt van een ... Read more

Published Date: Dec 16, 2024 (10 months, 2 weeks ago)
  • BleepingComputer
Clop ransomware claims responsibility for Cleo data theft attacks

12/16/24 update: Article updated to include new information about Cleo CVE-2024-50623 and CVE-2024-55956 flaws. The Clop ransomware gang has confirmed to BleepingComputer that they are behind the rece ... Read more

Published Date: Dec 15, 2024 (10 months, 2 weeks ago)
  • security.nl
VS bevestigt misbruik van kritiek Cleo-lek bij ransomware-aanvallen

Een kritieke kwetsbaarheid in de file sharing software van softwarebedrijf Cleo wordt gebruikt bij ransomware-aanvallen, zo heeft het Amerikaanse cyberagentschap CISA bevestigd. Eerder stelden beveili ... Read more

Published Date: Dec 14, 2024 (10 months, 2 weeks ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2024-55956 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 21, 2025

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-55956
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 21, 2025

    Action Type Old Value New Value
    Removed Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-55956
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 21, 2025

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-55956
  • Modified Analysis by [email protected]

    Mar. 14, 2025

    Action Type Old Value New Value
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Feb. 05, 2025

    Action Type Old Value New Value
    Added CWE CWE-77
    Removed CWE CWE-276
  • Initial Analysis by [email protected]

    Dec. 20, 2024

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE NIST CWE-77
    Added CPE Configuration OR *cpe:2.3:a:cleo:harmony:*:*:*:*:*:*:*:* versions up to (excluding) 5.8.0.24 *cpe:2.3:a:cleo:lexicom:*:*:*:*:*:*:*:* versions up to (excluding) 5.8.0.24 *cpe:2.3:a:cleo:vltrader:*:*:*:*:*:*:*:* versions up to (excluding) 5.8.0.24
    Changed Reference Type https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Advisory-CVE-Pending No Types Assigned https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Advisory-CVE-Pending Vendor Advisory
    Changed Reference Type https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update No Types Assigned https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update Vendor Advisory
    Changed Reference Type https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild No Types Assigned https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild Exploit, Third Party Advisory
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Dec. 18, 2024

    Action Type Old Value New Value
    Added Date Added 2024-12-17
    Added Due Date 2025-01-07
    Added Required Action Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
    Added Vulnerability Name Cleo Multiple Products Unauthenticated File Upload Vulnerability
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Dec. 16, 2024

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-276
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Dec. 13, 2024

    Action Type Old Value New Value
    Added Reference https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Update
    Added Reference https://www.huntress.com/blog/threat-advisory-oh-no-cleo-cleo-software-actively-being-exploited-in-the-wild
  • New CVE Received by [email protected]

    Dec. 13, 2024

    Action Type Old Value New Value
    Added 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.
    Added Reference https://support.cleo.com/hc/en-us/articles/28408134019735-Cleo-Product-Security-Advisory-CVE-Pending
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact