CVE-2023-39979Network attack vector

Unauthenticated access via weak random values

Published Sep 2, 2023 · Updated Sep 30, 2024

Authentication bypass in Moxa MXsecurity Series 1.0.1 and earlier allows remote attackers to gain unauthorized access via the web service. The authenticator uses an insufficiently large random-value space, allowing crafted requests to defeat login validation. The flaw requires network reachability to the web service and can expose or alter authenticated management information; no prior account is required.

CVSS severity9.8
Critical
EPSS probability0.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication bypass in Moxa MXsecurity Series 1.0.1 and earlier allows remote attackers to gain unauthorized access via the web service. The authenticator uses an insufficiently large random-value space, allowing crafted requests to defeat login validation. The flaw requires network reachability to the web service and can expose or alter authenticated management information; no prior account is required.

The record

CVE
CVE-2023-39979
Published
Sep 2, 2023
Updated
Sep 30, 2024
Vendor
Moxa
Product
MXsecurity Series
Classifications
CWE-334, CWE-330, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 30, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0 <=1.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moxa · MXsecurity Seriesversion=1.0 <=1.0.1

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8MoxaCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-334Small Space of Random Values
CWE-330Insufficiently Random Values
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo