CVE-2025-41703
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn unauthenticated remote attacker can cause a Denial of Service by turning off the output of the UPS via Modbus command.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceAn unauthenticated remote attacker can send Modbus commands to a UPS (Uninterruptible Power Supply) system to turn off its output, causing a denial of service. The vulnerability stems from a lack of authentication requirements for critical Modbus commands that control UPS functionality.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify UPS devices with Modbus interfacesInventory network-connected UPS systems and identify which ones expose Modbus communication (typically TCP port 502). Consult UPS vendor documentation or scan the network for devices responding on Modbus ports.Affected if The organization operates UPS devices that support Modbus communication.
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Verify Modbus interface network exposureDetermine whether the Modbus interface is accessible from network segments outside the trusted management network. Review firewall rules, ACLs, and network boundary configurations that control access to the UPS Modbus port.Affected if The Modbus interface is reachable from untrusted or external networks without filtering.
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Check if authentication is required for Modbus commandsConsult the UPS device documentation and configuration settings to determine whether authentication, authorization, or access control lists are enforced for Modbus commands that control power output (e.g., output shutdown commands). Attempt to send a read-only Modbus command without credentials to test basic access controls.Affected if The UPS accepts Modbus commands without requiring authentication or authorization.
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Assess network segmentation of UPS managementVerify whether UPS management interfaces, including Modbus, are isolated on a dedicated management VLAN or network segment separate from general production and user-accessible networks.Affected if UPS Modbus interfaces are on the same network segment as untrusted systems without logical or physical isolation.
A user is affected if their environment contains UPS devices with Modbus interfaces that are accessible from untrusted networks without authentication or network segmentation controls in place.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement authentication and authorization controls for Modbus commands, especially those affecting power output. Apply network segmentation to isolate UPS management interfaces from untrusted networks, and monitor for unauthorized Modbus command traffic.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2025-41703 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-41703 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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