What is the severity of ZDI-21-463?

The severity of ZDI-21-463 is classified as a high-severity privilege escalation vulnerability.

How do I fix ZDI-21-463?

To mitigate ZDI-21-463, users should apply the latest security patches provided by the X.Org development team.

Who is affected by ZDI-21-463?

ZDI-21-463 affects installations of the X.Org Server software that are vulnerable to privilege escalation.

What type of vulnerability is ZDI-21-463?

ZDI-21-463 is a privilege escalation vulnerability that allows local attackers to gain elevated rights.

What exploitation conditions exist for ZDI-21-463?

An attacker must first execute low-privileged code on the target system before exploiting ZDI-21-463.

Vulnerability/
ZDI-21-463

high

7.8

29/1/2025

ZDI-21-463: X.Org Server XChangeFeedbackControl Integer Underflow Privilege Escalation Vulnerability

This vulnerability allows local attackers to escalate privileges on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of XChangeFeedbackControl requests. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.

Affected Software	Affected Version	How to fix
X.Org Xserver

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Frequently Asked Questions

What is the severity of ZDI-21-463?
The severity of ZDI-21-463 is classified as a high-severity privilege escalation vulnerability.
How do I fix ZDI-21-463?
To mitigate ZDI-21-463, users should apply the latest security patches provided by the X.Org development team.
Who is affected by ZDI-21-463?
ZDI-21-463 affects installations of the X.Org Server software that are vulnerable to privilege escalation.
What type of vulnerability is ZDI-21-463?
ZDI-21-463 is a privilege escalation vulnerability that allows local attackers to gain elevated rights.
What exploitation conditions exist for ZDI-21-463?
An attacker must first execute low-privileged code on the target system before exploiting ZDI-21-463.

agent/references
agent/type
agent/softwarecombine
agent/severity
agent/title
agent/description
agent/event
agent/source
agent/tags
collector/zdi-advisory
source/ZDI
alias/ZDI-21-463
alias/ZDI-CAN-12549
alias/CVE-2021-3472
agent/software-canonical-lookup
agent/software-canonical-lookup-request
vendor/x.org
canonical/x.org xserver

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Frequently Asked Questions

What is the severity of ZDI-21-463?
The severity of ZDI-21-463 is classified as a high-severity privilege escalation vulnerability.
How do I fix ZDI-21-463?
To mitigate ZDI-21-463, users should apply the latest security patches provided by the X.Org development team.
Who is affected by ZDI-21-463?
ZDI-21-463 affects installations of the X.Org Server software that are vulnerable to privilege escalation.
What type of vulnerability is ZDI-21-463?
ZDI-21-463 is a privilege escalation vulnerability that allows local attackers to gain elevated rights.
What exploitation conditions exist for ZDI-21-463?
An attacker must first execute low-privileged code on the target system before exploiting ZDI-21-463.