Is CVE-2018-11421 actively exploited?

No active exploitation of CVE-2018-11421 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2018-11421 be exploited remotely?

Yes. CVE-2018-11421 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2018-11421?

CVE-2018-11421 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2018-11421

CRITICAL

CVE-2018-11421

CWE-319Published: July 3, 2019· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

Moxa OnCell G3100-HSPA Series version 1.6 Build 17100315 and prior use a proprietary monitoring protocol that does not provide confidentiality, integrity, and authenticity security controls. All information is sent in plain text, and can be intercepted and modified. The protocol is vulnerable to remote unauthenticated disclosure of sensitive information, including the administrator's password. Under certain conditions, it's also possible to retrieve additional information, such as content of HTTP requests to the device, or the previously used password, due to memory leakages.

NVD Source

Technical Analysis

CVE-2018-11421 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.