Advisory Details

March 17th, 2021

Microsoft Windows EFI Partition Incorrect Authorization Denial-of-Service Vulnerability

ZDI-21-330
ZDI-CAN-12299

CVE ID CVE-2021-26892
CVSS SCORE 5.5, (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Windows
VULNERABILITY DETAILS

This vulnerability allows local attackers to create a denial-of-service condition 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 Windows kernel. The issue results from improper authorization logic when accessing files in the EFI partition. An attacker can leverage this vulnerability to create a denial-of-service condition on the 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-2021-26892
DISCLOSURE TIMELINE
  • 2020-12-09 - Vulnerability reported to vendor
  • 2021-03-17 - Coordinated public release of advisory
CREDIT Abdelhamid Naceri (halov)
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