VulnerabilityPublished 22 Oct 2025

CVE-2025-41720: Sauter modulo 6 devices modu680-AS · Reliance on File Name or Extension of Externally-Supplied File

Affects Sauter modulo 6 devices modu680-ASSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Sauter modulo 6 devices modu680-AS	Affected =0.0.0	Fixed in–

AI-suggested

To mitigate CVE-2025-41720 effectively, organizations should implement the following specific measures: 1) Enforce strict server-side validation of uploaded files by inspecting file headers and content signatures rather than relying solely on file extensions; 2) Restrict file upload permissions to the minimum necessary user roles and disable uploads where not required; 3) Employ network segmentation to isolate devices like the modulo 6 from broader enterprise networks, limiting remote access; 4) Monitor device logs and network traffic for unusual file upload attempts or unexpected file types; 5) Apply any vendor-provided patches or firmware updates as soon as they become available; 6) If patching is not immediately possible, consider deploying web application firewalls or intrusion detection systems with custom rules to detect and block suspicious uploads; 7) Conduct regular security audits and penetration testing focused on device management interfaces; 8) Educate operational technology staff about the risks of file upload vulnerabilities and the importance of access controls. These targeted actions go beyond generic advice and address the specific nature of this vulnerability in embedded device environments.

Description

A low privileged remote attacker can upload arbitrary data masked as a png file to the affected device using the webserver API because only the file extension is verified.

Impact

For European organizations, particularly those in industrial automation, building management, and critical infrastructure sectors using Sauter modulo 6 devices, this vulnerability poses a risk of unauthorized modification of device files or configurations. Such unauthorized changes could disrupt automated processes, degrade system reliability, or provide a foothold for further attacks within operational technology (OT) environments. While the vulnerability does not directly expose sensitive data or cause denial of service, the integrity compromise could lead to subtle manipulations that are difficult to detect. This is especially concerning in sectors like manufacturing, energy, and facility management where these devices are commonly deployed. The ability for a low privileged remote attacker to upload arbitrary files increases the attack surface, potentially enabling supply chain attacks or lateral movement within networks. The absence of known exploits currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once the vulnerability is public. Therefore, European organizations should consider this vulnerability a moderate risk that requires timely mitigation to maintain operational security and trustworthiness of their control systems.

CWE-646Reliance on File Name or Extension of Externally-Supplied File (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product allows a file to be uploaded, but it relies on the file name or extension of the file to determine the appropriate behaviors. This could be used by attackers to cause the file to be misclassified and processed in a dangerous fashion.
Architecture and Design
Make decisions on the server side based on file content and not on file name or extension.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.12.2 (opens in a new tab)
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

sauter.csaf-tp.certvde.com/.well-known/csaf/white/2025/vde-2025-060.json (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Oct 2025, 07:08 UTC

WeaknessesCWE-646

Technical details

References

Community reviews

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