---
title: "CVE-2019-20485\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-2019-20485?format=md
keywords: index, follow
---

# CVE-2019-20485

Publication date 19 March 2020

Last updated 25 August 2025

---

Ubuntu priority

**Low**

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

## Cvss 3 Severity Score

**5.7 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2019-20485?format=md#impact-score)

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## Description

qemu/qemu\_driver.c in libvirt before 6.0.0 mishandles the holding of a
monitor job during a query to a guest agent, which allows attackers to
cause a denial of service (API blockage).

[Read the notes from the security team](https://ubuntu.com/security/CVE-2019-20485?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| libvirt | 20.04 LTS focal | Not affected |
| 19.10 eoan | Ignored end of life |
| 18.04 LTS bionic | Not affected |
| 16.04 LTS xenial | Not affected |
| 14.04 LTS trusty | 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-2019-20485?format=md#patch-details)

## Notes

---

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

it appears this CVE is only for the suspend job because it is
the only one that doesn't require write permissions.
In libvirt in bionic and older, there was no support for running
both agent monitor jobs and normal monitor jobs at the same.
Support for doing so was introduced in the following commit:
https://gitlab.com/libvirt/libvirt/-/commit/4621350f6d3dbca57bbd97829ff5d4efc3a51c97
As such, it would not appear that a malicious guest agent would
be able to block jobs in bionic and earlier, so marking as
not-affected.

### 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 |
| --- | --- |
| libvirt | * Upstream:   <https://libvirt.org/git/?p=libvirt.git;a=commit;h=cc1d1dbbd5fa18876a5ca8ac99a991b32ad49409> * Upstream:   <https://libvirt.org/git/?p=libvirt.git;a=commit;h=a663a860819287e041c3de672aad1d8543098ecc> |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

5.7 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 5.7 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-20485)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-20485)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-20485)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-20485)

### Other references

* <https://www.redhat.com/archives/libvir-list/2019-December/msg00295.html>
* <https://www.redhat.com/archives/libvir-list/2020-January/msg00569.html>
* <https://www.cve.org/CVERecord?id=CVE-2019-20485>