CVE-2023-3336Network attack vector

Account enumeration via password-recovery response differences

Published Jul 5, 2023 · Updated Nov 20, 2024

User enumeration in Moxa TN-5900 Series firmware 3.3 and earlier allows remote attackers to identify valid accounts through password recovery. The web login page's password-recovery flow returns an observable response difference when the supplied username identifies a valid account. No authentication is required; the disclosure reveals account validity and enables targeted password brute-force attempts, without reported configuration changes or service interruption.

CVSS severity5.3
Medium
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

User enumeration in Moxa TN-5900 Series firmware 3.3 and earlier allows remote attackers to identify valid accounts through password recovery. The web login page's password-recovery flow returns an observable response difference when the supplied username identifies a valid account. No authentication is required; the disclosure reveals account validity and enables targeted password brute-force attempts, without reported configuration changes or service interruption.

The record

CVE
CVE-2023-3336
Published
Jul 5, 2023
Updated
Nov 20, 2024
Vendor
Moxa
Product
TN-5900 Series
Classifications
CWE-204, CWE-203, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 5, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 20, 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=1.0 <=3.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Moxa · TN-5900 Seriesversion=1.0 <=3.3

Published CVSS scores

5.3MoxaCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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-204Observable Response Discrepancy
CWE-203Observable Discrepancy
T1087Account Discovery

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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