title: Nextcloud Server DNS pin middleware can be tricked into DNS rebinding allowing SSRF
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, the DNS pin middleware was vulnerable to DNS rebinding allowing an attacker to perform SSRF as a final result. 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-918: Server-Side Request Forgery (SSRF)
affected:
{
vendor: nextcloud
product: security-advisories
versions:
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
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
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5
baseSeverity: MEDIUM
confidentialityImpact: LOW
integrityImpact: NONE
privilegesRequired: LOW
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
version: 3.1
]