CVE intelligence and bounded remediation

CVE-2023-25159 — Nextcloud Nextcloud Server security vulnerability

Medium CVSS 5.3

Nextcloud Server is the file server software for Nextcloud, a self-hosted productivity platform, and Nextcloud Office is a document collaboration app for the same platform. Nextcloud Server 24.0.x prior to 24.0.8 and 25.0.x prior to 25.0.1, Nextcloud Enterprise Server 24.0.x prior to 24.0.8 and 25.0.x prior to 25.0.1, and Nextcloud Office (Richdocuments) App 6.x prior to 6.3.1 and 7.x prior to 7.0.1 have previews accessible without a watermark. The download should be hidden and the watermark should get applied. This issue is fixed in Nextcloud Server 25.0.1 and 24.0.8, Nextcloud Enterprise Server 25.0.1 and 24.0.8, and Nextcloud Office (Richdocuments) App 7.0.1 (for 25) and 6.3.1 (for 24). No known workarounds are available.

Severity
Medium
CVSS
5.3 (3.1)
Published
2023-02-13
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-284

Affected products

  • nextcloud / nextcloud_server
  • nextcloud / nextcloud_server / 24.0.2
  • nextcloud / nextcloud_server / 25.0.0
  • nextcloud / richdocuments
  • nextcloud / richdocuments / 7.0.0

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.