What is CVE-2024-55956?

CVE-2024-55956 is a critical-severity vulnerability in Cleo Harmony, classified under Command Injection. CVSS score: 9.8/10. Published 2024-12-13.

How severe is CVE-2024-55956?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2024-55956 known to be exploited?

Yes. CVE-2024-55956 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-12-17), indicating it is being actively exploited. 7 public proof-of-concept repositories are indexed.

RCE in Cleo Harmony

CVE-2024-55956

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 Autor…

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.938 (99.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

CWE-77 — Command Injection

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2024-12-17. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2025-01-07.

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

Known ransomware campaign use: yes.

Public proof-of-concept exploits

References

cve@mitre.org (Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Exploit, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2024-55956?: CVE-2024-55956 is a critical-severity vulnerability in Cleo Harmony, classified under Command Injection. CVSS score: 9.8/10. Published 2024-12-13.
How severe is CVE-2024-55956?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2024-55956 known to be exploited?: Yes. CVE-2024-55956 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-12-17), indicating it is being actively exploited. 7 public proof-of-concept repositories are indexed.