CVE-2024-50623
Cleo Harmony ≤ 5.8.0.21
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2024-50623 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Cleo Harmony. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified map to SI-3 (Malicious Code Protection) and CM-7 (Least Functionality) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Cleo Harmony, VLTrader, and LexiCom versions prior to 5.8.0.21 contain an unrestricted file upload and download flaw tracked as CVE-2024-50623. The issue stems from missing validation on file types and paths during transfer operations, allowing arbitrary files to be placed on or retrieved from the affected system and directly enabling remote code execution.
An unauthenticated attacker with network access can upload a malicious executable or script, then trigger its execution through the application or underlying operating system, achieving full control over the target host. The vulnerability carries a CVSS 3.1 score of 9.8, reflecting that no credentials or user interaction are required.
Cleo’s security advisory recommends immediate upgrade to version 5.8.0.21 or later for all three products. CISA has added the CVE to its Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild.
The associated EPSS score has reached a peak of 0.9694 with a current value of 0.9401, indicating sustained and widespread exploitation interest since disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-45217
Vulnerability Data
In Cleo Harmony before 5.8.0.21, VLTrader before 5.8.0.21, and LexiCom before 5.8.0.21, there is an unrestricted file upload and download that could lead to remote code execution.
- CWE(s)
- KEV Date Added
- 13 December 2024
Related Threats
Threat-Actor AttributionAI
MITRE ATT&CK Enterprise Techniques
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Affected Assets
Mitigating Controls
Control response
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V5.1.1
Mitigating Controls (NIST 800-53 r5) AI
Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.
Least functionality restricts the file types and automatic processing capabilities the system will accept.
Mobile-code controls define, authorize, and block unacceptable uploaded code before automatic processing occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.
Hardened configuration baselines can enforce allowed file types and processing rules.
Secure development practices include input validation and file-type restrictions that prevent this weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Configuration and acceptance testing verify that file-upload handling enforces allowed types and does not permit dangerous content to be stored or executed.
Secure-coding guidelines and security testing explicitly address restrictions on allowed file types and upload handling, reducing the risk that dangerous file uploads are accepted without validation.
Mandated testing for malicious content and known vulnerabilities reduces the likelihood that an outsourced component will contain or accept dangerous file types that could later be uploaded or executed.
Application allow-listing and pre-use scanning of received files directly blocks the introduction of executable content that has not been vetted, eliminating the primary vector for unrestricted dangerous file uploads.