CVE-2023-33183Network attack vector

Internal path disclosure via booking exception response

Published May 30, 2023 · Updated Jan 10, 2025

Information disclosure in Nextcloud Calendar 3.5.4 and earlier and 4.0.0 through 4.2.2 allows remote authenticated users to read internal paths. The appointment-booking controller exposes exception details containing internal website paths when notification email delivery fails because SMTP is unavailable. Exploitation requires a signed-in user, appointment-booking interaction, and failed SMTP delivery; the reported consequence is limited to path disclosure.

CVSS severity2.6
Low
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Nextcloud Calendar 3.5.4 and earlier and 4.0.0 through 4.2.2 allows remote authenticated users to read internal paths. The appointment-booking controller exposes exception details containing internal website paths when notification email delivery fails because SMTP is unavailable. Exploitation requires a signed-in user, appointment-booking interaction, and failed SMTP delivery; the reported consequence is limited to path disclosure.

The record

CVE
CVE-2023-33183
Published
May 30, 2023
Updated
Jan 10, 2025
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-285
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 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?

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

  1. Affected versionversion=< 3.5.5
  2. Affected versionversion=< 4.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=< 3.5.5; version=< 4.2.3

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
2.6GitHubCVSS:3.1/AV:N/AC:H/PR:L/UI:R/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-285Improper Authorization

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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