---
title: "CVE-2016-0721\n    | Ubuntu"
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-2016-0721?format=md
keywords: index, follow
---

# CVE-2016-0721

Publication date 21 April 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**8.1 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2016-0721?format=md#impact-score)

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## Description

Session fixation vulnerability in pcsd in pcs before 0.9.157.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| pcs | 16.04 LTS xenial | Not affected |
| 15.10 wily | Not in release |
| 14.04 LTS trusty | Not in release |
| 12.04 LTS precise | Not in release |

---

* [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**

8.1 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.1 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0721)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-0721)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-0721)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-0721)

### Other references

* <https://github.com/feist/pcs/commit/bc6ad9086857559db57f4e3e6de66762291c0774 (0.9.149)>
* <https://github.com/feist/pcs/commit/e9b28833d54a47ec441f6dbad0db96e1fc662a5b (0.9.149)>
* <https://github.com/feist/pcs/commit/acdbbe8307e6f4a36b2c7754765e732e43fe8d17 (0.9.149)>
* <https://www.cve.org/CVERecord?id=CVE-2016-0721>