Use-after-free in Microsoft Windows and Windows Server - CVE-2021-40449

Vulnerability identifier: #VU57249

CSH Severity: High

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-40449

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: The vulnerability is being exploited in the wild

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the Win32k NtGdiResetDC function in Microsoft Windows kernel. A local user can run a specially crafted program to trigger a use-after-free error, when the function ResetDC is executed a second time for the same handle during execution of its own callback, and execute arbitrary code with elevated privileges.

Note, the vulnerability is being actively exploited in the wild.

Microsoft Windows
Windows Server
Solutions Enabler Virtual Appliance
Solutions Enabler
Unisphere 360
Unisphere for PowerMax Virtual Appliance
Unisphere for PowerMax
VASA Provider Standalone

Install updates from vendor's website.

Solutions Enabler Virtual Appliance - addressed in versions 9.1.0.18, 9.2.3.0
Solutions Enabler - addressed in versions 9.1.0.18, 9.2.3.0
Unisphere 360 - addressed in versions 9.1.0.29, 9.2.3.3
Unisphere for PowerMax Virtual Appliance - addressed in versions 9.1.0.31, 9.2.3.4
Unisphere for PowerMax - addressed in versions 9.1.0.31, 9.2.3.4
VASA Provider Standalone - addressed in versions 9.1.0.723, 9.2.3.0

• Exploit #8957 - Kernel_Exploit (HEVD && CVE Exploit) (April 3, 2023)
• Exploit #7884 - Kernel_Exploit (HEVD & CVE Exploit) (May 24, 2022)
• Exploit #7482 - voidmap (Using CVE-2021-40449 to manual map kernel mode driver) (March 14, 2022)
• Exploit #7367 - CVE-2021-40449-NtGdiResetDC-UAF () (February 21, 2022)
• Exploit #7027 - cve-2021-40449-poc () (November 16, 2021)
• Exploit #6999 - Win32k NtGdiResetDC Use After Free Local Privilege Elevation (November 9, 2021)
• Exploit #6997 - CVE-2021-40449_poc (Exploit for CVE-2021-40449) (November 8, 2021)
• Exploit #6940 - CVE-2021-40449 (LPE exploit for a UAF in Windows (CVE-2021-40449).) (October 26, 2021)
• Exploit #6918 - CVE-2021-40449-Exploit (windows 10 14393 LPE) (October 22, 2021)
• Exploit #6908 - CallbackHell (Exploit for CVE-2021-40449 - Win32k Elevation of Privilege Vulnerability (LPE)) (October 18, 2021)
• Exploit #6906 - CallbackHell (PoC (DoS) for CVE-2021-40449 - Win32k Elevation of Privilege Vulnerability (LPE)) (October 18, 2021)

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449
• https://securelist.com/mysterysnail-attacks-with-windows-zero-day/104509/
• https://www.virustotal.com/gui/file/b7fb3623e31fb36fc3d3a4d99829e42910cad4da4fa7429a2d99a838e004366e

• Privilege escalation in Microsoft Windows kernel
• Multiple vulnerabilities in Dell Unisphere for PowerMax, Dell Solutions Enabler, Dell Unisphere 360, Dell VASA