CVE-2024-55956

Exp

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.

Published: 2024-12-13 Last update: 2025-11-04 Assigner: [email protected] Source: [email protected]

NVD Status：Analyzed，CVE State: published

View at NVD, CVE.org, EUVD

Threat Intelligence & Risk Assessment for CVE-2024-55956

KEV EPSS CVSS CWE Exploit-DB Affected

Conclusion & alert: CVE-2024-55956 is rated Critical Active Threat (100/100): CVSS Critical severity, with high exploitation likelihood (EPSS 93.80%, 100th percentile). Core evidence: CISA KEV confirms active exploitation (added 2024-12-17) affecting Cleo / Multiple Products. a weakness (CWE-77) Unauthenticated remote administrative access may be possible. EPSS rose +2.58% over the last day, indicating growing attacker interest. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2024-55956

Name: Cleo Multiple Products Unauthenticated File Upload Vulnerability · CISA KEV detail

Exploit added: 2024-12-17

Action due: 2025-01-07

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

Public exploit references (Exploit-DB) for CVE-2024-55956

EDB-ID	Source	Kind	Published	Link
—	nvd_ref	exploit_tag		Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2024-55956

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	91.22%	93.80%	+2.58%
2	2026-06-04	89.14%	91.22%	+2.08%
3	2026-05-22	—	89.14%	—

Full EPSS history (44 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-55956

CVSS metrics for this CVE.

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-55956

CWE-77 MITRE ↗

Affected software / configurations for CVE-2024-55956

Vendor	Product	Version	Raw CPE
cleo	harmony	< 5.8.0.24	cpe:2.3:a:cleo:harmony::::::::
cleo	lexicom	< 5.8.0.24	cpe:2.3:a:cleo:lexicom::::::::
cleo	vltrader	< 5.8.0.24	cpe:2.3:a:cleo:vltrader::::::::

References for CVE-2024-55956

URL	Tags
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	US Government Resource

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