Advisory Details

March 17th, 2021

Microsoft Windows Update Assistant Improper Access Control Privilege Escalation Vulnerability

ZDI-21-329
ZDI-CAN-12110

CVE ID CVE-2021-27070
CVSS SCORE 7.3, AV:L/AC:L/PR:L/UI:R/S:U/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 Windows Update Assistant. The issue results from incorrect permissions on a directory. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of Administrator.

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-2021-27070
DISCLOSURE TIMELINE
  • 2020-11-11 - Vulnerability reported to vendor
  • 2021-03-17 - Coordinated public release of advisory
CREDIT Abdelhamid Naceri (halov)
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