Advisory Details

August 3rd, 2021

Microsoft Edge Installer Directory Junction Privilege Escalation Vulnerability

ZDI-21-936
ZDI-CAN-13799

CVE ID CVE-2021-36928
CVSS SCORE 7.0, AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Edge
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of Microsoft Edge. 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 Edge Installer. By creating a directory junction, an attacker can abuse Edge Installer to delete a file. 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-2021-36928
DISCLOSURE TIMELINE
  • 2021-06-08 - Vulnerability reported to vendor
  • 2021-08-03 - Coordinated public release of advisory
CREDIT Abdelhamid Naceri
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