CVE-2021-4161Network attack vector

Administrator access via cleartext HTTP credentials

Published Dec 27, 2021 · Updated Sep 16, 2024

Cleartext credential transmission in Moxa MGate MB3180, MB3280, and MB3480 firmware allows remote attackers to obtain administrator credentials. The HTTP web console sends login details over unencrypted traffic, allowing a network-positioned attacker to capture and recover them. Exposure requires the HTTP console to be enabled and reachable; recovered credentials grant administrator access to the device's web server.

CVSS severity9.8
Critical
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext credential transmission in Moxa MGate MB3180, MB3280, and MB3480 firmware allows remote attackers to obtain administrator credentials. The HTTP web console sends login details over unencrypted traffic, allowing a network-positioned attacker to capture and recover them. Exposure requires the HTTP console to be enabled and reachable; recovered credentials grant administrator access to the device's web server.

The record

CVE
CVE-2021-4161
Published
Dec 27, 2021
Updated
Sep 16, 2024
Vendor
Moxa
Product
MGate MB3480 Series
Classifications
CWE-319, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=all 3.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moxa · MGate MB3480 Seriesversion=all 3.2
Moxa · MGate MB3280 Seriesversion=all 4.1
Moxa · MGate MB3180 Seriesversion=all <2.2

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
9.8ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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-319Cleartext Transmission of Sensitive Information
T1040Network Sniffing

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

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Your stack

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