CVE-2025-55084
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 · uneditedIn NetX Duo version before 6.4.4, the component of Eclipse Foundation ThreadX, there was an incorrect bound check in_nx_secure_tls_proc_clienthello_supported_versions_extension() in the extension version field.
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 confidenceNetX Duo ThreadX versions before 6.4.4 contain an incorrect bounds check in the TLS ClientHello supported_versions extension parser (_nx_secure_tls_proc_clienthello_supported_versions_extension). This could allow a malformed ClientHello message to trigger an out-of-bounds read when processing the extension version field during TLS handshake negotiation.
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< 6.4.4.202503CVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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 NetX Duo versionLocate the ThreadX NetX Duo library or header files in your build environment. Common locations include the NetX Duo source directory or compiled library. Check the version defined in nx_secure_version.h or similar version header, or inspect the library file metadata for version information.Affected if The version is earlier than 6.4.4.202503 (e.g., 6.4.3, 6.4.2, or any pre-6.4.4 release).
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Confirm TLS ClientHello processing is enabledReview your NetX Duo configuration (typically in tx_api.h or custom config files) for NX_SECURE_ENABLE or NX_SECURE_TLS_API definitions. Also verify your application code initializes TLS using nx_secure_tls_initialize or similar TLS initialization routines.Affected if TLS support is compiled into the build (NX_SECURE_ENABLE is defined).
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Check if TLS server or client mode processes ClientHelloInspect your application code for nx_secure_tls_server_certificate_add or nx_secure_tls_client_session_start calls. These indicate the device either acts as a TLS server accepting connections or as a TLS client initiating handshakes.Affected if The device operates as a TLS server accepting ClientHello messages, or as a TLS client that processes ServerHello with supported_versions extension.
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Verify supported_versions extension handling is activeThis is a TLS 1.3 feature. Check if your TLS configuration specifies TLS 1.3 support via NX_SECURE_TLS_ENABLE_TLS_1_3 or similar compile-time flags, or if the TLS handshake negotiates TLS 1.3 with connected peers.Affected if TLS 1.3 is enabled and the device negotiates TLS 1.3 with remote peers during handshake.
You are affected if your NetX Duo version is below 6.4.4.202503 AND TLS with TLS 1.3 support is enabled, causing the device to parse ClientHello supported_versions extensions during handshake negotiations.
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.
dbcve · scoped6.4.4.202503
Upgrade NetX Duo to version 6.4.4 or later which contains the corrected bounds check in the supported_versions extension parsing routine.
6.4.4.202503
- Obtain NetX Duo version 6.4.4.202503 or later from the Eclipse Foundation GitHub repository or official distribution channels
- Replace the existing NetX Duo library in your project with the updated version 6.4.4.202503
- Rebuild and test your application to ensure the TLS client hello extension processing now correctly handles bounds checking
- Verify the fix by confirming the _nx_secure_tls_proc_clienthello_supported_versions_extension() function now properly validates the extension version field bounds before reading
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-55084 — 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-2025-55084 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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