CVE-2025-27803
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 · uneditedThe devices do not implement any authentication for the web interface or the MQTT server. An attacker who has network access to the device immediately gets administrative access to the devices and can perform arbitrary administrative actions and reconfigure the devices or potentially gain access to sensitive data.
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 · high confidenceMultiple device models lack authentication on both their web interface and MQTT server, allowing any network-adjacent attacker to gain immediate administrative access and execute arbitrary commands or access sensitive data.
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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
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 affected device types on the networkInventory all network-connected devices that provide a web interface and/or MQTT service. Focus on IoT devices, industrial controllers, smart home hubs, or embedded systems where vendor documentation indicates no built-in authentication.Affected if Any such device with unauthenticated web or MQTT services is present on the network
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Test web interface authenticationAttempt to access the device web interface from a network-adjacent host without providing any credentials. Try accessing common paths like /, /admin, /api, or the device root IP. Observe if administrative functions or sensitive data are accessible without a login prompt.Affected if The web interface grants access to administrative features or sensitive data without requiring any authentication credentials
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Test MQTT broker authenticationConnect to the device MQTT port (typically 1883 or 8883) using an MQTT client tool (such as mosquitto_pub or mosquitto_sub) without providing username or password. Subscribe to topics or attempt to publish messages.Affected if The MQTT server accepts connections and allows topic subscription or publication without any authentication
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Verify network exposure of servicesScan the network for open ports corresponding to web interfaces (80, 443, 8080, 8443) and MQTT services (1883, 8883) on suspect devices. Determine if these services are accessible from network segments beyond the local management VLAN.Affected if The unauthenticated web interface or MQTT services are reachable from network segments other than a dedicated management network
The environment is affected if any network-connected device has its web interface or MQTT server accessible without authentication, allowing immediate administrative access.
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 dataContact the device vendor for patched firmware that implements proper authentication on both the web interface and MQTT server; network segmentation can limit exposure until patches are applied.
- Consultation8.0 h
- Testing12.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-27803 — 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-2025-27803 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data