---
title: "CVE-2017-9524\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-2017-9524?format=md
keywords: index, follow
---

# CVE-2017-9524

Publication date 6 July 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2017-9524?format=md#impact-score)

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## Description

The qemu-nbd server in QEMU (aka Quick Emulator), when built with the
Network Block Device (NBD) Server support, allows remote attackers to cause
a denial of service (segmentation fault and server crash) by leveraging
failure to ensure that all initialization occurs before talking to a client
in the nbd\_negotiate function.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| qemu | 17.04 zesty | Fixed 1:2.8+dfsg-3ubuntu2.4 |
| 16.10 yakkety | Ignored end of life |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | Not affected |
| qemu-kvm | 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 |

---

* [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-2017-9524?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 |
| --- | --- |
| qemu | * Upstream:   <https://git.qemu.org/gitweb.cgi?p=qemu.git;a=commit;h=df8ad9f128c15aa0a0ebc7b24e9a22c9775b67af> * Upstream:   <https://git.qemu.org/gitweb.cgi?p=qemu.git;a=commit;h=0c9390d978cbf61e8f16c9f580fa96b305c43568> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-9524)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-9524)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-9524)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-9524)

### Related Ubuntu Security Notices (USN)

+ [USN-3414-1](https://usn.ubuntu.com/USN-3414-1)
+ QEMU vulnerabilities
+ 13 September 2017

### Other references

* <https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg06240.html>
* <https://lists.gnu.org/archive/html/qemu-devel/2017-06/msg02321.html>
* <https://www.cve.org/CVERecord?id=CVE-2017-9524>