CVE-2020-27184Network attack vector

Session disclosure via cleartext Telnet management

Published May 14, 2021 · Updated Aug 4, 2024

Cleartext transmission in Moxa NPort IA5000A Series allows man-in-the-middle attackers to read Telnet management sessions. The management service sends authentication credentials, device configuration, firmware version, and other sensitive data over Telnet without transport encryption. Man-in-the-middle attackers must occupy the client-device network path and can passively capture the exchange; no integrity or availability impact is reported.

CVSS severity5.9
Medium
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext transmission in Moxa NPort IA5000A Series allows man-in-the-middle attackers to read Telnet management sessions. The management service sends authentication credentials, device configuration, firmware version, and other sensitive data over Telnet without transport encryption. Man-in-the-middle attackers must occupy the client-device network path and can passively capture the exchange; no integrity or availability impact is reported.

The record

CVE
CVE-2020-27184
Published
May 14, 2021
Updated
Aug 4, 2024
Vendor
Moxa
Product
NPort IA5000A Series
Classifications
CWE-319, T1040
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 versions

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moxa · NPort IA5000A Seriesversion=All versions

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N
5.9NIST NVDCVSS:3.1/AV:N/AC:H/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.

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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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