CVE-2025-41703Public exploitNetwork attack vector

Unauthenticated UPS shutdown via Modbus register write

Published Oct 14, 2025 · Updated Oct 14, 2025

Missing authentication in Phoenix Contact QUINT4-UPS EIP VC:00 through VC:07 allows remote attackers to shut off UPS output. The Modbus configuration interface accepts an unauthenticated write that sets bit 11 of the Code Set Parameters register at address 0x1040, disabling the output. Network access to Modbus/TCP is sufficient, and the resulting loss of UPS output interrupts powered equipment without disclosing data or changing unrelated device functions.

CVSS severity7.5
High
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in Phoenix Contact QUINT4-UPS EIP VC:00 through VC:07 allows remote attackers to shut off UPS output. The Modbus configuration interface accepts an unauthenticated write that sets bit 11 of the Code Set Parameters register at address 0x1040, disabling the output. Network access to Modbus/TCP is sufficient, and the resulting loss of UPS output interrupts powered equipment without disclosing data or changing unrelated device functions.

The record

CVE
CVE-2025-41703
Published
Oct 14, 2025
Updated
Oct 14, 2025
Vendor
Phoenix Contact
Product
QUINT4-UPS/24DC/24DC/20/EIP
Classifications
CWE-306, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=VC:00 <=VC:07

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Phoenix Contact · QUINT4-UPS/24DC/24DC/20/EIPversion=VC:00 <=VC:07
Phoenix Contact · QUINT4-UPS/24DC/24DC/5/EIPversion=VC:00 <=VC:07
Phoenix Contact · QUINT4-UPS/24DC/24DC/40/EIPversion=VC:00 <=VC:07
Phoenix Contact · QUINT4-UPS/24DC/24DC/10/EIPversion=VC:00 <=VC:07

Published CVSS scores

7.5CERT@VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T0814Denial of Service

Public exploit references

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

Technologies

Your stack

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Your stack

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