Threats / Cleo / CVE-2024-55956
CVE-2024-55956
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Cleo Multiple Products vulnerability
Cleo managed file transfer products contain an unrestricted file upload vulnerability allowing unauthenticated attackers to execute arbitrary commands via the Autorun directory.
Verdict
Today item, not a backlog item.
An unauthenticated attacker can upload malicious bash or PowerShell scripts to a default Autorun directory, achieving remote code execution on the host system without authentication. This vulnerability is actively exploited in ransomware campaigns.
CISA KEV Yes · 2024-12-174Ransomware use Flagged4EPSS 0.93804 (verify live)5CVSS 9.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3Exploit Weaponized · public exploit · Metasploit module · nuclei template12
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
43 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-12-17), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.93804 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) · Affected: Cleo, Multiple Products. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-276 Incorrect Default Permissions — weakness family: Authorization / access control.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 4 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a functional/weaponized public exploit). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I upload a malicious script file to the Autorun directory without authentication.
Business
The organization's file transfer infrastructure is compromised without requiring valid credentials.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I leverage default Autorun settings to execute my uploaded bash or PowerShell commands automatically.
Business
Arbitrary code runs with the privileges of the Cleo service, potentially system-level access.
3
Lateral reach — past segmentation narrative 3
Attacker
I establish persistent command execution and lateral movement within the network.
Business
Attackers gain foothold for ransomware deployment, data exfiltration, and infrastructure compromise.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05