CVE-2021-31954: Microsoft Windows CLFS Heap-based Buffer Overflow Privilege Escalation Vulnerability
First published: Tue Jun 08 2021(Updated: )
This vulnerability allows local attackers to escalate privileges on affected installations of Microsoft Windows. 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 clfs.sys driver. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM.
Credit: secure@microsoft.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Microsoft Windows 7 | ||
| Microsoft Windows 7 | ||
| Microsoft Windows Server 2008 R2 | ||
| Microsoft Windows Server 2012 R2 | ||
| Microsoft Windows Server 2012 R2 | ||
| Microsoft Windows Server | =2004 | |
| Microsoft Windows Server 2008 R2 | ||
| Microsoft Windows Server | =20H2 | |
| Microsoft Windows RT | ||
| Microsoft Windows Server | ||
| Microsoft Windows Server | ||
| Microsoft Windows Server | ||
| Microsoft Windows Server | ||
| Microsoft Windows Server | ||
| Microsoft Windows Server | ||
| Microsoft Windows 8.1 | ||
| Microsoft Windows 8.1 | ||
| Microsoft Windows Server 2019 | ||
| Microsoft Windows Server 2019 | ||
| Microsoft Windows Server 2016 | ||
| Microsoft Windows Server 2016 | ||
| Windows 10 | =20H2 | |
| Windows 10 | =20H2 | |
| Windows 10 | =20H2 | |
| Windows 10 | =1809 | |
| Windows 10 | =1809 | |
| Windows 10 | =1809 | |
| Windows 10 | =1607 | |
| Windows 10 | =1607 | |
| Windows 10 | =21H1 | |
| Windows 10 | =21H1 | |
| Windows 10 | =21H1 | |
| Windows 10 | =1909 | |
| Windows 10 | =1909 | |
| Windows 10 | =1909 | |
| Windows 10 | ||
| Windows 10 | ||
| Windows 10 | =2004 | |
| Windows 10 | =2004 | |
| Windows 10 | =2004 | |
| Windows 10 | ||
| Windows 10 | =20h2 | |
| Windows 10 | =21h1 | |
| Windows 10 | =1607 | |
| Windows 10 | =1909 | |
| Windows 10 | =2004 | |
| Microsoft Windows 7 | =sp1 | |
| Microsoft Windows | ||
| Microsoft Windows RT | ||
| Microsoft Windows Server | =sp2 | |
| Microsoft Windows Server | =r2-sp1 | |
| Microsoft Windows Server | ||
| Microsoft Windows Server | =r2 | |
| Microsoft Windows Server 2016 | ||
| Microsoft Windows Server 2016 | =20h2 | |
| Microsoft Windows Server 2016 | =2004 | |
| Microsoft Windows Server 2019 | ||
| Microsoft Windows Operating System |
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Reference Links
Frequently Asked Questions
What is the severity of CVE-2021-31954?
CVE-2021-31954 has been rated as a critical vulnerability due to its potential for privilege escalation on affected systems.
Who is affected by CVE-2021-31954?
CVE-2021-31954 affects various versions of Microsoft Windows, including Windows 10 and Windows Server.
How do I fix CVE-2021-31954?
To fix CVE-2021-31954, apply the latest security patches provided by Microsoft for your specific Windows version.
What type of vulnerability is CVE-2021-31954?
CVE-2021-31954 is a privilege escalation vulnerability that allows local attackers to execute malicious code with elevated privileges.
What must an attacker do to exploit CVE-2021-31954?
An attacker must first obtain the ability to execute low-privileged code on the target system to exploit CVE-2021-31954.
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