Cleo Releases Patch for Critical Vulnerabilities Exploited in the Wild

Summary

OEM	Cleo
Severity	Critical
CVSS score	9.8
CVE	CVE-2024-55956, CVE-2024-50623
Exploited in Wild	Yes
Patch/Remediation Available	Yes
Advisory Version	1.0

Overview

The Clop ransomware group has exploited critical vulnerabilities in Cleo’s Managed File Transfer (MFT) solutions, specifically targeting Cleo Harmony, VLTrader, and LexiCom. These vulnerabilities, identified as CVE-2024-50623 and CVE-2024-55956, allow unauthenticated attackers to execute arbitrary code on affected systems, leading to potential data breaches and system compromises.

Vulnerability Name	CVE ID	Product Affected	Severity	CVSS Score	Fixed Version
Unauthenticated Command Execution	CVE-2024-55956	Cleo products	Critical	9.8	5.8.0.24 or latest
Unrestricted File Upload/Download Vulnerability	CVE-2024-50623	Cleo products	Critical	9.8	5.8.0.24 or latest

Technical Summary

CVE ID	System Affected	Vulnerability Details	Impact
CVE-2024-55956	Cleo Harmony, VLTrader, LexiCom	This flaw enables unauthenticated users to import and execute arbitrary Bash or PowerShell commands on the host system by leveraging the default settings of the Autorun directory. Attackers can write a ZIP file containing a malicious XML file describing a new host. The malicious XML file contained a Mailbox action associated with the new host, which when run would execute an arbitrary OS command.	Execution of arbitrary commands, resulting in full system compromise.
CVE-2024-50623	Cleo Harmony, VLTrader, LexiCom	This vulnerability permits unauthenticated attackers to upload and download files without restrictions via the ‘/Synchronization’ endpoint. By uploading malicious files, attackers can achieve remote code execution. The exploitation involves writing malicious code to specific files, such as “webserverAjaxSwingconftemplatesdefault-pagebody-footerVL.html”, which is then leveraged to execute an attacker-controlled payload, potentially in the form of a webshell.	Unauthorized file manipulation and potential system compromise.

Remediations

Update Cleo Harmony, VLTrader, and LexiCom to the updated version 5.8.0.24 or latest one.

Recommendations

It is strongly advised to move any internet-exposed Cleo systems behind a firewall until patches are applied to prevent unauthorized exploitation.
Disable autorun files in Cleo software by clearing the “Autorun Directory” field under “Options” to limit the attack surface; this doesn’t resolve the file-write vulnerability.
Implement monitoring for signs of the “Cleopatra” backdoor and other malicious activities associated with Clop ransomware.
Conduct a thorough audit of your systems to identify any malicious files or abnormal system behavior associated with Cleo software. This includes checking logs, directories, and network traffic for unusual activities related to the known exploit chain.
If you have an EDR solution, block the attacker IPs associated with the exploit to prevent further external communication with compromised systems.
Ensure regular backups of critical data are performed and stored securely offline to facilitate recovery in case of any ransomware attack.

IOCs

Based on the research
These are the attacker IP addresses embedded in the encoded PowerShell

IP Address IOCs	File IOCs
176.123.5[.]126	60282967-dc91-40ef-a34c-38e992509c2c.xml
5.149.249[.]226	healthchecktemplate.txt
185.181.230[.]103	healthcheck.txt
209.127.12[.]38
181.214.147[.]164
192.119.99[.]42

References

Tags:CISO CleoExploitation CleoSoftware CVE2024 CXO Cybersecurity CyberThreats Intrucept NetworkSecurity PatchManagement RemoteCodeExecution ThreatAdvisory Threatintelligence Vulnerabilitymitigation