---
title: "CVE-2015-7849\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-2015-7849?format=md
keywords: index, follow
---

# CVE-2015-7849

Publication date 7 August 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**8.8 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2015-7849?format=md#impact-score)

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## Description

Use-after-free vulnerability in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x
before 4.3.77 allows remote authenticated users to possibly execute
arbitrary code or cause a denial of service (crash) via crafted packets.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2015-7849?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| ntp | 15.10 wily | Not affected |
| 15.04 vivid | Not affected |
| 14.04 LTS trusty | Not affected |
| 12.04 LTS precise | Not affected |

---

* [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-2015-7849?format=md#patch-details)

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

precise to wily don't look vulnerable

### 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 |
| --- | --- |
| ntp | * Upstream:   [9c22e66](https://github.com/ntp-project/ntp/commit/9c22e66c8f2be6aa0c846f0d9804db20f93c105d) * Upstream:   [1bb4015](https://github.com/ntp-project/ntp/commit/1bb401576f412532d8cdcca5509b85ad29605913) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.8 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | 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 | 8.8 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/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-2015-7849)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2015-7849)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2015-7849)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2015-7849)

### Other references

* <http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner>
* <http://blog.talosintel.com/2015/10/ntpd-vulnerabilities.html>
* <http://talosintel.com/reports/TALOS-2015-0054/>
* <https://www.cve.org/CVERecord?id=CVE-2015-7849>