CVE-2021-4011: X.Org Server SwapCreateRegister Out-Of-Bounds Access Local Privilege Escalation Vulnerability
A flaw was found in xorg-x11-server in versions before 21.1.2 and before 1.20.14. An out-of-bounds access can occur in the SwapCreateRegister function. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Other sources
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 SwapCreateRegister requests. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.
— ZDI
Affected Software
Remediation
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is CVE-2021-4011?
CVE-2021-4011 is a vulnerability that allows local attackers to escalate privileges on affected installations of X.Org Server.
How can this vulnerability be exploited?
An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
What is the severity of CVE-2021-4011?
CVE-2021-4011 has a severity rating of 7.8 (High).
Which versions of X.Org Server are affected by CVE-2021-4011?
Versions up to and including 21.1.2 of X.Org Server are affected by CVE-2021-4011.
How can I fix CVE-2021-4011?
To fix CVE-2021-4011, update X.Org Server to version 21.1.2 or later.