CVE-2021-27077: Microsoft Windows win32kfull MulDrawStream Untrusted Pointer Dereference Privilege Escalation Vulnerability
First published: Tue Mar 09 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 win32kfull.sys driver. The issue results from dereferencing a NULL pointer. 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 Server | =2004 | |
| Microsoft Windows 7 | ||
| Microsoft Windows Server 2008 R2 | ||
| Microsoft Windows Server 2008 R2 | ||
| Microsoft Windows Server 2012 R2 | ||
| Microsoft Windows Server 2012 R2 | ||
| Microsoft Windows Server | =1909 | |
| Microsoft Windows 7 | ||
| 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 2016 | ||
| Microsoft Windows Server 2016 | ||
| Microsoft Windows Server 2019 | ||
| Microsoft Windows Server 2019 | ||
| Windows 10 | =20H2 | |
| Windows 10 | =20H2 | |
| Windows 10 | =20H2 | |
| Windows 10 | =1803 | |
| Windows 10 | =1809 | |
| Windows 10 | =1809 | |
| Windows 10 | =1809 | |
| Windows 10 | =1607 | |
| Windows 10 | =1607 | |
| Windows 10 | =1909 | |
| Windows 10 | =1909 | |
| Windows 10 | =1909 | |
| Windows 10 | ||
| Windows 10 | =1803 | |
| Windows 10 | =1803 | |
| Windows 10 | ||
| Windows 10 | =2004 | |
| Windows 10 | =2004 | |
| Windows 10 | =2004 | |
| Windows 10 | ||
| Windows 10 | =20h2 | |
| Windows 10 | =1607 | |
| Windows 10 | =1803 | |
| Windows 10 | =1809 | |
| Windows 10 | =1909 | |
| Windows 10 | =2004 | |
| Microsoft Windows 7 | =sp1 | |
| Microsoft Windows | ||
| Microsoft Windows RT | ||
| Microsoft Windows Server | =r2-sp1 | |
| Microsoft Windows Server | =r2-sp2 | |
| Microsoft Windows Server | ||
| Microsoft Windows Server | =r2 | |
| Microsoft Windows Server 2016 | ||
| Microsoft Windows Server 2016 | =20h2 | |
| Microsoft Windows Server 2016 | =1909 | |
| Microsoft Windows Server 2016 | =2004 | |
| Microsoft Windows Server 2019 | ||
| Microsoft Windows Operating System |
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Reference Links
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27077
- https://www.zerodayinitiative.com/advisories/ZDI-21-287/
- https://www.zerodayinitiative.com/advisories/ZDI-21-403/
- https://www.zerodayinitiative.com/advisories/ZDI-21-482/
- https://www.zerodayinitiative.com/advisories/ZDI-21-499/
- https://www.zerodayinitiative.com/advisories/ZDI-21-494/
- https://www.zerodayinitiative.com/advisories/ZDI-21-497/
- https://www.zerodayinitiative.com/advisories/ZDI-21-501/
- https://www.zerodayinitiative.com/advisories/ZDI-21-500/
- https://www.zerodayinitiative.com/advisories/ZDI-21-496/
- https://www.zerodayinitiative.com/advisories/ZDI-21-498/
- https://www.zerodayinitiative.com/advisories/ZDI-21-495/
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-27077 (Advisory)
Frequently Asked Questions
What is the severity of CVE-2021-27077?
CVE-2021-27077 has a CVSS score indicating it allows local privilege escalation, making it a significant security threat.
How do I fix CVE-2021-27077?
To fix CVE-2021-27077, apply the relevant security patches provided by Microsoft for your affected Windows version.
Which versions of Windows are affected by CVE-2021-27077?
CVE-2021-27077 affects various versions of Microsoft Windows, including Windows 10, Windows Server, and Windows 7.
Who can exploit CVE-2021-27077?
CVE-2021-27077 can be exploited by local attackers who already have the ability to execute low-privileged code on the system.
Is there a workaround for CVE-2021-27077?
Currently, Microsoft recommends applying the security updates as the primary mitigation for CVE-2021-27077, and there are no official workarounds.
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