Vulnerability report

Exploitation attempts observed in the wild Confirmed confidence In CISA KEV

CVE-2024-50623

["Harmony" Remote Code Execution

Cleo / ["Harmony"

Watch CVE-2024-50623 Browse KEV feed
Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Exploitation attempts observed in the wild
EPSS
98.6%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2024-50623 is an unauthenticated vulnerability affecting Cleo ["Harmony" and 2 other products. 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...

Have exploitation attempts been observed?

Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Listed in CISA KEV. Also reported by third-party sources. Confidence is confirmed.

Who is affected?

Cleo / ["Harmony".

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

["Harmony" Remote Code Execution

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.

Published
27 Oct 2024
Exploitation Attempts Reported
13 Dec 2024
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

nessus_scanner malware ransomware cisa nuclei_scanner

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation attempts observed in the wild

CISA

Recorded 13 Dec 2024

A trusted third party reported exploitation attempts.

Targeted by malware-related exploitation attempts

CISA

Recorded 13 Dec 2024

Exploitation attempts against this vulnerability are associated with malware-related payloads.

Proof of concept available

GitHub

Recorded 11 Dec 2024

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2024-12-13 00:00 UTC
The Shadowserver 2026-07-24 00:00 UTC
CVE 2026-07-31 04:10 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2024/CVE-2024-50623.yaml 25 Apr 2025
Nessus https://www.tenable.com/plugins/nessus/213295 20 Dec 2024

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

98.6%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Unrestricted Upload of File with Dangerous Type CWE-434

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Cleo Harmony < 5.8.0.21 - Arbitary File Read

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation attempts

  1. 04:10 UTC

    KEV confirmed by CVE

    Exploitation attempts reported by an external source

  2. 00:00 UTC

    KEV confirmed by The Shadowserver

    Exploitation attempts reported by an external source

  3. 14:20 UTC

    Public PoC available

    Public proof-of-concept code published

  4. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  5. 20:33 UTC

    Nessus plugin available

    Scanner coverage available

  6. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  7. 00:00 UTC

    Targeted by malware-related exploitation attempts

    Malware-related exploitation attempts or payloads reported

  8. 00:00 UTC

    CVE published

    Vulnerability disclosed publicly

  9. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2024-50623

Sample API response 
{
  "cve_id": "CVE-2024-50623",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.98607,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}