CVE-2023-45150

Inviting excessive long email addresses to a calendar event makes the Nextcloud server unresponsive

Severity Score

4.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track*

*SSVC

Descriptions

Nextcloud calendar is a calendar app for the Nextcloud server platform. Due to missing precondition checks the server was trying to validate strings of any length as email addresses even when megabytes of data were provided, eventually making the server busy and unresponsive. It is recommended that the Nextcloud Calendar app is upgraded to 4.4.4. The only workaround for users unable to upgrade is to disable the calendar app.

Nextcloud calendar es una aplicación de calendario para la plataforma del servidor Nextcloud. Debido a la falta de comprobaciones de condiciones previas, el servidor intentaba validar cadenas de cualquier longitud como direcciones de correo electrónico incluso cuando se proporcionaban megabytes de datos, lo que eventualmente hacía que el servidor estuviera ocupado y no respondiera. Se recomienda actualizar la aplicación Calendario Nextcloud a 4.4.4. El único workaround para los usuarios que no pueden actualizar es desactivar la aplicación de calendario.

*Credits: N/A

CVSS Scores

NISTv3.1 4.3

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

* Common Vulnerability Scoring System

SSVC

Decision:Track*

Exploitation

Poc

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2023-10-04 CVE Reserved
2023-10-16 CVE Published
2024-09-15 EPSS Updated
2024-09-16 CVE Updated
2024-09-16 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-354: Improper Validation of Integrity Check Value
CWE-400: Uncontrolled Resource Consumption

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC
https://hackerone.com/reports/2058337	2024-09-16

URL	Date	SRC
https://github.com/nextcloud/calendar/pull/5358	2023-10-20

URL	Date	SRC
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r936-8gwm-w452	2023-10-20

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nextcloud Search vendor "Nextcloud"		Calendar Search vendor "Nextcloud" for product "Calendar"				>= 1.0 < 4.4.4 Search vendor "Nextcloud" for product "Calendar" and version " >= 1.0 < 4.4.4"		-		Affected