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NetX Duo Web EUVDEUVD-2026-105132

| CVE-2026-94018 HIGH
Use of Uninitialized Variable (CWE-457)
2026-10-20 eclipse
8.8
CVSS 4.0 · Vendor: eclipse
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Reach NetX Duo Web HTTP server over network
  2. Exploit
    Send malformed PUT with Content-Length underflow
  3. Execution
    Trigger dereference/free of uninitialized pointer
  4. Impact
    Crash service or device (DoS)

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Variable initialization checks
Exploitation Conditions

The device must be running the NetX Duo Web add-on's HTTP server and have it reachable by the attacker; the trigger is a single PUT request whose Content-Length is crafted to cause an underflow, after which an uninitialized pointer is dereferenced and freed. No authentication is required (PR:N) and no user interaction is needed. The principal limiting factor is deployment: only devices that have enabled/compiled in the NetX Duo Web HTTP server component and expose it to the attacker's network are affected - devices using NetX Duo without the Web add-on, or with the HTTP server not network-reachable, are not exposed.

Impact

All available CVSS signals point to a genuinely easy-to-reach flaw: the supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N) describes a remote, low-complexity, unauthenticated trigger needing no user interaction and no special attack requirements, consistent with the description's 'single malformed request.' However, the impact profile tempers the raw 8.8 score: VC:N/VI:L/VA:H means the realistic outcome is denial of service (service/device crash) with limited integrity effect and no confidentiality loss - not remote code execution or data theft. No EPSS probability, no CISA KEV entry, and no POC indicator were provided, so there is no evidence of active or imminent exploitation; the exploitation status is therefore 'no public exploit identified at time of analysis.' A notable conflict exists: the input Tag 'Information Disclosure' contradicts the CVSS confidentiality metric (VC:N) and the CWE-457 (use of uninitialized variable) crash semantics in the description, which read as a memory-safety/DoS issue rather than a disclosure. This should be verified against the Eclipse advisory before treating it as a confidentiality risk. Net: a legitimately high-severity, trivially triggerable DoS in an embedded networking stack, but without exploitation evidence it is a prioritize-for-patching issue rather than a confirmed emergency - with the caveat that embedded/RTOS devices are often hard to patch, which raises operational urgency.

Exploit ScenarioDerived

An attacker able to reach a device running the NetX Duo Web add-on HTTP server sends a single crafted PUT request whose Content-Length field is manipulated to cause an underflow. The server mishandles the condition by dereferencing and releasing an uninitialized pointer (CWE-457), crashing the HTTP service or device. No public exploit code has been identified at the time of analysis.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 20, 2026

Denial of service in the Eclipse ThreadX NetX Duo Web add-on's HTTP server, which mishandles a Content-Length underflow while processing a PUT request and ends up dereferencing and freeing an uninitialized pointer. The flaw is reachable by an unauthenticated remote client with a single malformed request (CVSS 4.0 AV:N/AC:L/AT:N/PR:N/UI:N), making the realistic outcome a crash of the HTTP service or the whole device (VC:N/VI:L/VA:H) rather than code execution or data exposure. Only deployments that have compiled in and network-exposed the Web add-on's HTTP server are affected; devices running NetX Duo without that component are not exposed, and no public exploit code was identified at time of analysis.

RemediationAI

Apply the fix referenced in the Eclipse ThreadX NetX Duo security advisory GHSA-wjxf-gjm5-jh5q (https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-wjxf-gjm5-jh5q); the intelligence feed contains no explicit fixed version string, so the patched release must be confirmed against that advisory before upgrading, and downstream vendors (silicon/board and RTOS integrators) should be checked for their own rebuilt images since NetX Duo is almost always delivered inside a vendor SDK. Where immediate upgrade is not possible, remove exposure: drop the Web add-on's HTTP server from the build configuration (nx_web_http_server component) if it is not a product requirement - this eliminates the attack surface at the cost of losing the embedded web UI or REST endpoint; or block the HTTP/HTTPS listener at the network boundary so only trusted management hosts can reach it, accepting that any allowed host retains the ability to crash the service. If PUT is not part of the exposed API, disabling or rejecting PUT handling at the server or a fronting reverse proxy removes the trigger path, though it must be verified that the length parsing occurs before method rejection. Monitoring for repeated device resets or HTTP task faults on exposed NetX Duo devices provides detection, and no vendor workaround beyond patching is documented in the available references.

Affected VersionsENISA

Eclipse ThreadX - NetX Duo 6.4.2 ≤6.5.1.202602

Affected Packages

euvd eclipse_threadx_netx_duo no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

NetX Duo is the embedded IPv4/IPv6 TCP/IP stack maintained under the Eclipse ThreadX (formerly Azure RTOS) umbrella, and its optional Web add-on supplies the HTTP/HTTPS server used on many microcontroller-class and RTOS devices. The defect is classified CWE-457 (Use of an Uninitialized Variable): when the server parses a PUT request whose Content-Length value is crafted to underflow (an unsigned arithmetic wrap during body-length bookkeeping), an error/cleanup path operates on a pointer that was never initialized, then both dereferences and releases it. Because this is memory-unsafe C operating on attacker-controlled length fields, the immediate consequence is a fault in the server task - a crash or teardown of the HTTP service with possible device-level reset - with a limited integrity side effect from the erroneous free, and no assessed confidentiality impact (VC:N). The supplied CPE is version-wildcarded (cpe:2.3:a:eclipse_foundation:eclipse_threadx_-_netx_duo:*:*:*:*:*:*:*:*), meaning the feed provides no granular version cutoff, so any NetX Duo release bundling the Web HTTP server should be treated as potentially affected until mapped to the vendor advisory. Note that one source tag references information disclosure, but the authoritative assessed vector shows C:N, so information leakage is not an established impact.

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Severity by source

Vendor (eclipse) PRIMARY 8.8 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
vuln.today AI 8.2 HIGH

Single unauthenticated remote request (AV:N/AC:L/PR:N/UI:N); uninitialized pointer free crashes the service (A:H) with limited integrity effect (I:L) and no confidentiality impact (C:N).

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (eclipse).

CVSS VectorVendor: eclipse

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
None
Vulnerable system: Integrity
Low
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

DescriptionCVE.org

The Web add-on's HTTP server dereferences and releases an uninitialized pointer when it detects a Content-Length underflow while processing a PUT request. The condition is reachable by an unauthenticated remote client with a single malformed request.

Technical POC Analysis

CWE-457 (Use of Uninitialized Variable), with the access-of-uninitialized-pointer facet CWE-824 also assigned.

Full technical POC analysis - root cause, step-by-step exploitation and patch breakdown - is part of the Pro and Business plans.

Executive ViewAI

Why It Matters

The optional HTTP server component of the Eclipse ThreadX NetX Duo Web add-on can be forced to crash by a single malformed request from any unauthenticated network client, taking the device's web interface offline and, in some configurations, the entire device. The exposure is limited to embedded and connected-product deployments that have both compiled in and network-exposed this add-on, but for those fleets the effect is repeated, trivially triggered loss of availability on devices that are often difficult to physically reach or restart. Leadership should care because this is a low-effort, high-repeatability availability risk to fielded devices rather than a data-breach scenario, and no vendor fix is currently available.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: restrict network reachability of the Web add-on HTTP server to trusted management segments via ACLs, firewall rules, or VLAN segmentation; front the device with a proxy or gateway that rejects PUT methods and malformed or negative Content-Length headers; rebuild firmware without the Web add-on HTTP server where the functionality is not required; monitor for HTTP service crashes and unexpected reboots to detect exploitation attempts; and verify watchdog/recovery behavior so a crash does not leave devices in a persistent failed state.

Threat Intelligence Overview

EPSS Score
0.4%
Top 67% exploitable
Prevalence
Medium
embedded RTOS web server add-on, common in IoT but feature-gated
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.4%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
Yes
Human Impact
High
Technical Impact
Partial

Priority Score

44
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +44
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

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