CVE-2024-40125: An arbitrary file upload vulnerability in the Media Manager function of Closed-Loop Technology CLESS Server v4

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2024-40125 is a critical-severity flaw (CVSS 9.8) affecting cless server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An arbitrary file upload vulnerability in the Media Manager function of Closed-Loop Technology CLESS Server v4.5.2 allows attackers to execute arbitrary code via uploading a crafted PHP file to the upload endpoint.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 41%)
CISA exploited list	No
Weakness	CWE-434
Published	2024-09-19
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: closed-loop

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-09-19 19:15 UTCPublished CVE record published
2026-06-17 07:45 UTCUpdated Record last modified

closed-loop cless server DOWNGRADE

Affected: 4.5.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.5.2

1. Check installed version

apt-cache policy cless-server || rpm -q cless-server || cless-server --version

2. No fixed release: DOWNGRADE to a release before 4.5.2 (Debian / Ubuntu)

apt-cache madison cless-server sudo apt install cless-server=<VERSION_BEFORE_4.5.2> sudo apt-mark hold cless-server

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list cless-server sudo dnf downgrade cless-server-<VERSION_BEFORE_4.5.2> sudo dnf versionlock add cless-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2024-40125?

cless server: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2024-40125 being exploited?

CVE-2024-40125 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-40125 affect?

CVE-2024-40125 affects cless server. Severity is critical (CVSS 9.8). An arbitrary file upload vulnerability in the Media Manager function of Closed-Loop Technology CLESS Server v4.5.2 allows attackers to execute arbitrary code via uploading a crafted PHP file to the upload endpoint.

How urgent is CVE-2024-40125?

Priority 59/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

References

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