title: Nextcloud Server vulnerable to attacker enabling/disabling birthday calendar for any user
description: Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Server and starting in version 22.0.0 and prior to versions 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Enterprise Server, an attacker could enable and disable the birthday calendar for any user on the same server. Nextcloud Server 25.0.11, 26.0.6, and 27.1.0 and Nextcloud Enterprise Server 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, and 27.1.0 contain patches for this issue. No known workarounds are available.
problem types: CWE-639: Authorization Bypass Through User-Controlled Key
affected:
{
vendor: nextcloud
product: security-advisories
versions:
version: >= 25.0.0, < 25.0.11, status: affected
version: >= 26.0.0, < 26.0.6, status: affected
version: >= 27.0.0, < 27.1.0, status: affected
version: >= 22.0.0, < 22.2.10.16, status: affected
version: >= 23.0.0, < 23.0.12.11, status: affected
version: >= 24.0.0, < 24.0.12.7, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 4.3
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
version: 3.1
]