CVE-2017-13721

Publication date 9 October 2017

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

In X.Org Server (aka xserver and xorg-server) before 1.19.4, an attacker authenticated to an X server with the X shared memory extension enabled can cause aborts of the X server or replace shared memory segments of other X clients in the same session.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
xorg-server-lts-xenial	17.04 zesty	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Fixed 2:1.18.3-1ubuntu2.3~trusty3
xorg-server-lts-wily	17.04 zesty	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
xorg	17.04 zesty	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
xorg-hwe-16.04	17.04 zesty	Not in release
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not in release
xorg-server	17.04 zesty	Fixed 2:1.19.3-1ubuntu1.2
	16.04 LTS xenial	Fixed 2:1.18.4-0ubuntu0.6
	14.04 LTS trusty	Fixed 2:1.15.1-0ubuntu2.10
xorg-server-hwe-16.04	17.04 zesty	Not in release
	16.04 LTS xenial	Fixed 2:1.19.3-1ubuntu1~16.04.3
	14.04 LTS trusty	Not in release
xorg-server-lts-utopic	17.04 zesty	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
xorg-server-lts-vivid	17.04 zesty	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
xorg-server	Upstream: ?id=b95

Severity score breakdown

Parameter	Value
Base score	4.7 · Medium
Attack vector	Local
Attack complexity	High
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-3453-1
X.Org X server vulnerabilities
12 October 2017