CVE-2023-33372
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 · uneditedConnected IO v2.1.0 and prior uses a hard-coded username/password pair embedded in their device's firmware used for device communication using MQTT. An attacker who gained access to these credentials is able to connect to the MQTT broker and send messages on behalf of devices, impersonating them. in order to sign and verify JWT session tokens, allowing attackers to sign arbitrary session tokens and bypass authentication.
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 confidenceConnected IO devices v2.1.0 and prior contain hard-coded MQTT credentials embedded in the firmware. Attackers who obtain these credentials can connect to the MQTT broker and impersonate devices by sending messages on their behalf. Additionally, the compromised firmware allows attackers to sign and verify arbitrary JWT tokens, completely bypassing authentication mechanisms.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 2.1.0CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 device firmware versionAccess the device management interface or check the firmware file metadata to determine the installed version number. For command-line access, use 'version' or 'show system info' commands if available.Affected if The firmware version is 2.1.0 or lower (any version up to and including 2.1.0).
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Extract and inspect firmware for hardcoded MQTT credentialsIf you have access to the firmware image (via device backup, download from vendor portal, or firmware extraction), decompress the firmware and search binary or configuration files for plaintext MQTT credentials (look for strings containing 'mqtt', 'broker', username/password patterns associated with MQTT protocol).Affected if Any hardcoded MQTT username/password or broker connection strings are found embedded in the firmware binary or configuration files.
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Analyze JWT signing implementationInspect the firmware or application binaries for JWT signing logic. Look for static symmetric keys (HMAC) used for token signing, or examine the JWT validation endpoint to determine if the signing key can be extracted from the firmware image.Affected if A static, hardcoded key is used for JWT signing/verification, or the JWT implementation allows unsigned or self-signed tokens to be accepted for authentication.
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Check MQTT broker authentication logsReview MQTT broker logs (if you have access) for connection attempts using embedded or predictable credentials, or check if multiple devices share identical authentication credentials.Affected if Multiple devices authenticate with identical MQTT credentials, indicating shared hardcoded values.
A device is affected if it runs Connected IO firmware version 2.1.0 or lower and contains hardcoded MQTT credentials or uses a static key for JWT signing.
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 dataReplace hard-coded credentials with dynamically generated, unique credentials per device, implement secure credential storage, and rebuild the JWT signing mechanism using proper secret management. Deploy patched firmware to all affected devices and rotate any exposed credentials immediately.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-33372 — 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-2023-33372 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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