CVE-2025-41720Network attack vector

Authenticated arbitrary file upload via extension-only validation

Published Oct 22, 2025 · Updated Oct 22, 2025

Arbitrary file upload in SAUTER EY-modulo 5 and modulo 6 controllers before firmware 6.0 or 3.2.0 allows remote authenticated users to write data. The webserver API accepts attacker-supplied content as a PNG after checking only the filename extension, without validating the file data. Low-privileged API access is required, and the published record establishes unauthorized data storage but reports no code execution.

CVSS severity4.3
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Arbitrary file upload in SAUTER EY-modulo 5 and modulo 6 controllers before firmware 6.0 or 3.2.0 allows remote authenticated users to write data. The webserver API accepts attacker-supplied content as a PNG after checking only the filename extension, without validating the file data. Low-privileged API access is required, and the published record establishes unauthorized data storage but reports no code execution.

The record

CVE
CVE-2025-41720
Published
Oct 22, 2025
Updated
Oct 22, 2025
Vendor
Fr. Sauter AG
Product
SAUTER EY-modulo 5 modu524
Classifications
CWE-646, T1105
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.0 <Firmware v6.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Fr. Sauter AG · SAUTER EY-modulo 5 modu524version=0.0 <Firmware v6.0
Fr. Sauter AG · SAUTER EY-modulo 5 ecos504/505version=0.0 <Firmware v6.0
Fr. Sauter AG · SAUTER modulo 6 modu660-ASversion=0.0.0 <Firmware v3.2.0
Fr. Sauter AG · SAUTER modulo 6 modu612-LCversion=0.0.0 <Firmware v3.2.0
Fr. Sauter AG · SAUTER EY-modulo 5 modu525version=0.0 <Firmware v6.0
Fr. Sauter AG · SAUTER modulo 6 modu680-ASversion=0.0.0 <Firmware v3.2.0

Published CVSS scores

4.3CERT VDECVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-646Reliance on File Name or Extension of Externally-Supplied File
T1105Ingress Tool Transfer

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo