---
title: "CVE-2020-8903\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-2020-8903?format=md
keywords: index, follow
---

# CVE-2020-8903

Publication date 22 June 2020

Last updated 3 July 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-2020-8903?format=md#impact-score)

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## Description

A vulnerability in Google Cloud Platform's guest-oslogin versions between
20190304 and 20200507 allows a user that is only granted the role
"roles/compute.osLogin" to escalate privileges to root. Using their
membership to the "adm" group, users with this role are able to read the
DHCP XID from the systemd journal. Using the DHCP XID, it is then possible
to set the IP address and hostname of the instance to any value, which is
then stored in /etc/hosts. An attacker can then point
metadata.google.internal to an arbitrary IP address and impersonate the GCE
metadata server which make it is possible to instruct the OS Login PAM
module to grant administrative privileges. All images created after
2020-May-07 (20200507) are fixed, and if you cannot update, we recommend
you edit /etc/group/security.conf and remove the "adm" user from the OS
Login entry.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| gce-compute-image-packages | 26.04 LTS resolute | Fixed 20190801-0ubuntu5 |
| 25.10 questing | Fixed 20190801-0ubuntu5 |
| 25.04 plucky | Fixed 20190801-0ubuntu5 |
| 24.10 oracular | Fixed 20190801-0ubuntu5 |
| 24.04 LTS noble | Fixed 20190801-0ubuntu5 |
| 23.10 mantic | Fixed 20190801-0ubuntu5 |
| 23.04 lunar | Fixed 20190801-0ubuntu5 |
| 22.10 kinetic | Fixed 20190801-0ubuntu5 |
| 22.04 LTS jammy | Fixed 20190801-0ubuntu5 |
| 21.10 impish | Fixed 20190801-0ubuntu5 |
| 21.04 hirsute | Fixed 20190801-0ubuntu5 |
| 20.10 groovy | Fixed 20190801-0ubuntu5 |
| 20.04 LTS focal | Fixed 20190801-0ubuntu4.1 |
| 19.10 eoan | Fixed 20190801-0ubuntu1.1 |
| 18.04 LTS bionic | Fixed 20190801-0ubuntu1~18.04.1 |
| 16.04 LTS xenial | Fixed 20190801-0ubuntu1~16.04.1 |
| 14.04 LTS trusty | Vulnerable |

---

* [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**

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:3.1/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-2020-8903)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-8903)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2020-8903)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2020-8903)

### Other references

* <https://cloud.google.com/support/bulletins/#gcp-2020-008>
* <https://github.com/GoogleCloudPlatform/guest-oslogin/pull/29>
* <https://gitlab.com/gitlab-com/gl-security/gl-redteam/red-team-tech-notes/-/tree/master/oslogin-privesc-june-2020>
* <https://www.cve.org/CVERecord?id=CVE-2020-8903>