---
title: "CVE-2016-9566\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-2016-9566?format=md
keywords: index, follow
---

# CVE-2016-9566

Publication date 15 December 2016

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.8 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2016-9566?format=md#impact-score)

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## Description

base/logging.c in Nagios Core before 4.2.4 allows local users with access
to an account in the nagios group to gain root privileges via a symlink
attack on the log file. NOTE: this can be leveraged by remote attackers
using CVE-2016-9565.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| nagios3 | 17.04 zesty | Fixed 3.5.1.dfsg-2.1ubuntu5 |
| 16.10 yakkety | Fixed 3.5.1.dfsg-2.1ubuntu3.1 |
| 16.04 LTS xenial | Fixed 3.5.1.dfsg-2.1ubuntu1.1 |
| 14.04 LTS trusty | Fixed 3.5.1-1ubuntu1.1 |
| 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)
* [Patch details](https://ubuntu.com/security/CVE-2016-9566?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| nagios3 | * Upstream:   [c29557d](https://github.com/NagiosEnterprises/nagioscore/commit/c29557dec91eba2306f5fb11b8da4474ba63f8c4) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.8 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.8 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9566)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2016-9566)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2016-9566)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2016-9566)

### Related Ubuntu Security Notices (USN)

+ [USN-3253-1](https://usn.ubuntu.com/USN-3253-1)
+ Nagios vulnerabilities
+ 3 April 2017

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2016-9566>