CVE-2024-4739: Medium Access Control Flaw in Moxa MXsecurity

CVE-2024-4739 is a medium severity access control flaw in Moxa MXsecurity software version 1.1.0 and prior, scored 5.3. With a valid authenticator, an attacker could pose as an authorized user and reach a resource they should not. Moxa's advisory points to firmware 2.2.0 or higher.

What's affected

The Moxa advisory MPSA-231878 covers the MXsecurity series, software version v1.1.0 and prior. It describes two issues in one bulletin: this one, and CVE-2024-4740, which concerns hard-coded credentials. The weakness here is CWE-749, exposed dangerous method or function, and the vendor impact line says an attacker could gain access to the resource.

Moxa scores it CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N, 5.3 Medium, and marks it as an unauthenticated remote exploit. The NVD record carries the same score. The two sources agree, so there is no severity conflict. One wording point: the description says the attacker needs a valid authenticator, while the vector says no privileges are required. Read that as the vendor's shorthand for how the access is gained, and check the advisory if the difference matters to your risk model.

The KEV flag is false.

How to check if you're exposed

MXsecurity is Moxa's network security management product for industrial networks, so the check is about the product install, not a package manager.

1. Find your MXsecurity servers and read the installed software version in the management interface.
2. Compare it to the affected range, v1.1.0 and prior.
3. Check whether the management interface is reachable from the internet or from user networks.
4. Pull the list of accounts and API access with administrative rights.

What to do now

1. Upgrade to firmware 2.2.0 or higher through the Moxa Software Licensing Portal, as the advisory instructs.
2. Minimize network exposure so the device is not accessible from the internet.
3. When remote access is needed, use secure methods such as a VPN.
4. Review access logs for logins from unknown addresses.
5. Rotate administrator passwords after the upgrade.
6. Read the full advisory, including the section on the second CVE.

Why it matters

Access control checks are the gate in front of every resource. When a resource can be reached without a proper check, the other protections around it, passwords and roles included, do little good. The class here is exposure of a function that was meant to be restricted.

Management platforms deserve attention even at a medium score. MXsecurity sits over the network devices it manages, so information from it can help someone plan the next step. A medium score with an exposed management port is a good reason to fix the exposure as well as the version.

Quick check

Sources

• Moxa advisory MPSA-231878
• NVD record data for CVE-2024-4739

Last reviewed: 19 October 2026.