---
title: CVE-2016-9464
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2016-9464
---

# CVE-2016-9464

Publication date 28 March 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**4.3 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2016-9464#impact-score)

Toggle side navigation

## 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.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| nextcloud | 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Not in release |
| 17.04 zesty | Not in release |
| 16.10 yakkety | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Not in release |
| owncloud | 18.10 cosmic | Not in release |
| 18.04 LTS bionic | Not in release |
| 17.10 artful | Not in release |
| 17.04 zesty | Not in release |
| 16.10 yakkety | Not in release |
| 16.04 LTS xenial | Not in release |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Ignored end of life |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

4.3 · Medium

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | Low |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | None |
  | Integrity impact | Low |
  | Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 4.3 · Medium |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9464)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-9464)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-9464)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-9464)

### Other references

* <https://github.com/nextcloud/server/commit/3387e5d00fcf6b2ea6b285a091e5743f545e7202>
* <https://github.com/nextcloud/server/commit/7289cb5ec0b812992ab0dfb889744b94bc0994f0>
* <https://github.com/nextcloud/server/commit/a5471b4a3e3f30e99e4de39c97c0c3b3c2f1618f>
* <https://github.com/nextcloud/server/commit/e2c4f4f9aa11bc92e8f2212cce73841b922187e8>
* <https://hackerone.com/reports/153905>
* <https://nextcloud.com/security/advisory/?id=nc-sa-2016-007>
* <https://www.cve.org/CVERecord?id=CVE-2016-9464>