TI-2023-16360 Aliases CVE-2023-33183

Error in calendar when booking an appointment reveals the full path of the website

LOW 20CWE-285Published 2023-05-30 · Updated 2025-01-10

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Security bypass
Confidentiality · integrity · availability: Low · None · None
Fix status: Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-285.

Summary

Calendar app for Nextcloud easily sync events from various devices with your Nextcloud. Some internal paths of the website are disclosed when the SMTP server is unavailable. It is recommended that the Calendar app is updated to 3.5.5 or 4.2.3

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00438 38th percentileScored 2026-11-07

Fix Fixed security-advisories (nextcloud): 3.5.5, 4.2.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
nextcloud	security-advisories	before 3.5.5; before 4.2.3	3.5.5, 4.2.3	Patch available	CNA

security-advisories Vendornextcloud Affected before 3.5.5; before 4.2.3 Fixed in 3.5.5, 4.2.3 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:nextcloud:calendar::::::::	before 3.5.5; 4.0.0 to before 4.2.3	Vulnerable	nextcloud

cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:* Versions before 3.5.5; 4.0.0 to before 4.2.3 Vulnerable ·nextcloud

Remediation

Fix · CNA security-advisories (nextcloud) Fixed in 3.5.5, 4.2.3

Timeline

2026-10-02 Threatist record created from CVE-2023-33183

References

Patch 1

https://github.com/nextcloud/calendar/pull/4938

Advisory 1

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-2792-2734-hr7j

TI-2022-08650 Command Injection in Appointment Emails for Nextcloud Calendar CVSS 3.1CRITICAL 9.8
TI-2023-24171 Inviting excessive long email addresses to a calendar event makes the Nextcloud server unresponsive CVSS 3.1MEDIUM 4.3
TI-2023-26171 Calendar app returns full stacktrace when an error happens while editing appointment CVSS 3.1MEDIUM 6.5
TI-2025-40933 Nextcloud Calendar app used predictable proposal participant tokens CVSS 3.1MEDIUM 6.5
TI-2025-40961 Nextcloud Calendar attachments of local files are offered to downloaded CVSS 3.1MEDIUM 5.7
TI-2018-02759 Cross-site scripting in Nextcloud Calendar application CVSS 3.1MEDIUM 4.8

See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences