Cyber Resilience

CVE-2025-4140

HighPublic PoC

Published: 30 April 2025

Published
30 April 2025
Modified
12 May 2025
KEV Added
Patch
CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0128 80.0th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-4140 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Netgear Ex6120 Firmware. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation of Remote Services (T1210); ranked in the top 20.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

A critical buffer overflow vulnerability exists in Netgear EX6120 firmware version 1.0.3.94 within the function sub_30394. The issue, tracked as CVE-2025-4140 and assigned CWE-119 and CWE-120, arises from improper handling of the host argument and carries a CVSS 4.0 score of 8.7 reflecting network attack vector, low attack complexity, and low privileges required.

An authenticated remote attacker can supply a crafted host value to trigger the overflow, resulting in high impact to confidentiality, integrity, and availability on the affected device. The vendor was notified prior to disclosure but provided no response, leaving the flaw unpatched in the listed firmware.

Public references consist of a technical write-up and proof-of-concept details hosted on GitHub along with Vuldb entries; no official mitigation guidance or firmware update has been issued by Netgear. The associated EPSS score remains flat at 0.0128 with no observed increase after publication.

EU & UK References

Vulnerability details

A vulnerability, which was classified as critical, has been found in Netgear EX6120 1.0.3.94. Affected by this issue is the function sub_30394. The manipulation of the argument host leads to buffer overflow. The attack may be launched remotely. The vendor…

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was contacted early about this disclosure but did not respond in any way.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Why these techniques?

Remote buffer overflow in the sub_30394 function (via 'host' argument) enables exploitation of the device's remote service, likely the web management interface, for potential remote code execution.

Affected Assets

netgear
ex6120 firmware
1.0.3.94

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119 CWE-120

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References