(Pwn2Own) Microsoft Windows win32kbase Type Confusion Local Privilege Escalation Vulnerability

August 14th, 2025
ZDI-25-843 ZDI-CAN-27188

CVE ID

CVE-2025-50168

CVSS Score

8.8 AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected Vendors

Microsoft

Affected Products

Windows

Vulnerability Details

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 win32kbase driver. The issue results from the lack of proper validation of user-supplied data, which can result in a type confusion condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM.

Additional Details

Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-50168

Disclosure Timeline

  • 2025-05-23 - Vulnerability reported to vendor
  • 2025-08-14 - Coordinated public release of advisory
  • 2025-08-14 - Advisory Updated

Credit

Hyeonjin Choi (@d4m0n_8) of Out Of Bounds

Back to Advisories