---
title: "CVE-2017-12164\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-2017-12164?format=md
keywords: index, follow
---

# CVE-2017-12164

Publication date 26 July 2018

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**6.4 · Medium**

[Score breakdown](https://ubuntu.com/security/CVE-2017-12164?format=md#impact-score)

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## Description

A flaw was discovered in gdm 3.24.1 where gdm greeter was no longer setting
the ran\_once boolean during autologin. If autologin was enabled for a
victim, an attacker could simply select 'login as another user' to unlock
their screen.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2017-12164?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| gdm3 | 17.10 artful | Fixed 3.26.0-1ubuntu1 |
| 17.04 zesty | Fixed 3.24.1-0ubuntu0.2 |
| 16.04 LTS xenial | Not affected |
| 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-2017-12164?format=md#patch-details)

## Notes

---

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

according with RHEL it's a side effect introduced in gdm-3.24.1
affecting only artful and zesty.

---

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

introduced by ff98b2817014684ae1acec78ff06f0f461a56a9f

### 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 |
| --- | --- |
| gdm3 | * Upstream:   [?id=798](https://git.gnome.org/browse/gdm/commit/?id=798be427d2cf9bd2cdcffb75cacc3ab7fd1b1234) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

6.4 · Medium

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 6.4 · Medium |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-12164)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-12164)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-12164)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-12164)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2017-12164>