CVE-2023-38327Network attack vector

Unauthenticated user enumeration via free-busy response discrepancy

Published Jul 11, 2025 · Updated Jul 15, 2025

User enumeration in EGroupWare 17.1.20190111 allows remote attackers to identify application users through calendar/freebusy.php responses. The endpoint returns observably different server responses depending on whether a supplied calendar user exists, exposing account validity without authentication. Network access to the web endpoint is sufficient, and the bounded impact is disclosure of valid user identities rather than data modification or service interruption.

CVSS severity5.3
Medium
EPSS probability0.30%
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 EGroupWare 17.1.20190111 allows remote attackers to identify application users through calendar/freebusy.php responses. The endpoint returns observably different server responses depending on whether a supplied calendar user exists, exposing account validity without authentication. Network access to the web endpoint is sufficient, and the bounded impact is disclosure of valid user identities rather than data modification or service interruption.

The record

CVE
CVE-2023-38327
Published
Jul 11, 2025
Updated
Jul 15, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-203, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 15, 2025Record 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

5.3CISA-ADPCVSS: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-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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