CVE-2023-1393

Description

A flaw was found in X.Org Server Overlay Window. A Use-After-Free may lead to local privilege escalation. If a client explicitly destroys the compositor overlay window (aka COW), the Xserver would leave a dangling pointer to that window in the CompScreen structure, which will trigger a use-after-free later.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
xorg-server-lts-wily	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored end of standard support
xorg-server-lts-xenial	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored end of standard support
xwayland	25.10 questing	Fixed 2:22.1.8-1ubuntu1
	25.04 plucky	Fixed 2:22.1.8-1ubuntu1
	24.10 oracular	Fixed 2:22.1.8-1ubuntu1
	24.04 LTS noble	Fixed 2:22.1.8-1ubuntu1
	23.10 mantic	Fixed 2:22.1.8-1ubuntu1
	23.04 lunar	Fixed 2:22.1.8-1ubuntu1
	22.10 kinetic	Fixed 2:22.1.3-2ubuntu0.4
	22.04 LTS jammy	Fixed 2:22.1.1-1ubuntu0.6
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
xorg-server	25.10 questing	Fixed 2:21.1.7-1ubuntu3
	25.04 plucky	Fixed 2:21.1.7-1ubuntu3
	24.10 oracular	Fixed 2:21.1.7-1ubuntu3
	24.04 LTS noble	Fixed 2:21.1.7-1ubuntu3
	23.10 mantic	Fixed 2:21.1.7-1ubuntu3
	23.04 lunar	Fixed 2:21.1.7-1ubuntu3
	22.10 kinetic	Fixed 2:21.1.4-2ubuntu1.7
	22.04 LTS jammy	Fixed 2:21.1.3-2ubuntu2.9
	20.04 LTS focal	Fixed 2:1.20.13-1ubuntu1~20.04.8
	18.04 LTS bionic	Fixed 2:1.19.6-1ubuntu4.15
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Needs evaluation
xorg-server-hwe-16.04	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Not in release
xorg-server-hwe-18.04	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Fixed 2:1.20.8-2ubuntu2.2~18.04.11
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
xorg-server-lts-utopic	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored end of standard support
xorg-server-lts-vivid	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Ignored end of standard support
tigervnc	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Fixed 1.12.0+dfsg-8ubuntu0.23.10.1
	23.04 lunar	Fixed 1.12.0+dfsg-8ubuntu0.23.04.1
	22.04 LTS jammy	Fixed 1.12.0+dfsg-4ubuntu0.22.04.1
	20.04 LTS focal	Fixed 1.10.1+dfsg-3ubuntu0.20.04.1
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Ignored end of standard support
	14.04 LTS trusty	Ignored end of standard support

Notes

mdeslaur

xorg server is actually the xorg-server package the xorg package only contains docs xwayland package contains parts of xorg-server This is ZDI-CAN-19866 tigervnc needs a no-change rebuild once xorg-server is fixed

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: 26ef545

Severity score breakdown

Parameter	Value
Base score	7.8 · High
Attack vector	Local
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

USN-5986-1
X.Org X Server vulnerability
29 March 2023

Cvss 3 Severity Score