Advisory Details

August 14th, 2023

Microsoft Windows CLFS Incorrect Integer Conversion Local Privilege Escalation Vulnerability

ZDI-23-1067
ZDI-CAN-20977

CVE ID CVE-2023-36900
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 clfs.sys driver. A crafted BLF file can trigger an incorrect integer calculation before allocating a buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel.

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-2023-36900
DISCLOSURE TIMELINE
  • 2023-05-23 - Vulnerability reported to vendor
  • 2023-08-14 - Coordinated public release of advisory
CREDIT Anonymous
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