CVE-2021-44554Public exploitNetwork attack vector

Unauthenticated account enumeration via response discrepancies

Published Dec 20, 2021 · Updated Aug 4, 2024

User enumeration in Cybele Software Thinfinity VirtualUI before 3.0 allows remote attackers to identify Windows account names. The unauthenticated /changePassword endpoint returns distinguishable messages for existing and nonexistent username values, with wording varying by configured language. Network access to the endpoint is sufficient, and the disclosed account names can support password guessing without exposing passwords or modifying accounts.

CVSS severity5.3
Medium
EPSS probability1.03%
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 Cybele Software Thinfinity VirtualUI before 3.0 allows remote attackers to identify Windows account names. The unauthenticated /changePassword endpoint returns distinguishable messages for existing and nonexistent username values, with wording varying by configured language. Network access to the endpoint is sufficient, and the disclosed account names can support password guessing without exposing passwords or modifying accounts.

The record

CVE
CVE-2021-44554
Published
Dec 20, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-203, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 20, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/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 exploitPublished

Weakness, pattern, technique

CWE-203Observable Discrepancy
T1087Account Discovery

Public exploit references

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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