CVE-2020-25697
Publication date 26 May 2021
Last updated 25 August 2025
Ubuntu priority
Cvss 3 Severity Score
Description
A privilege escalation flaw was found in the Xorg-x11-server due to a lack of authentication for X11 clients. This flaw allows an attacker to take control of an X application by impersonating the server it is expecting to connect to.
Status
| Package | Ubuntu Release | Status | 
|---|---|---|
| libx11 | 22.04 LTS jammy | Ignored | 
| 20.04 LTS focal | Ignored | |
| 18.04 LTS bionic | Ignored | |
| 16.04 LTS xenial | Ignored | |
| 14.04 LTS trusty | Ignored | 
Notes
mdeslaur
as of 2021-05-19, there is no upstream fix for this issue. This is a long-standing X11 design limitation and is difficult to exploit. We will not be releasing updates for this issue.
Severity score breakdown
| Parameter | Value | 
|---|---|
| Base score |  | 
| Attack vector | Local | 
| Attack complexity | High | 
| Privileges required | Low | 
| User interaction | None | 
| Scope | Unchanged | 
| Confidentiality | High | 
| Integrity impact | High | 
| Availability impact | High | 
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |