Advisory Details

September 16th, 2021

Microsoft Visual Studio Incorrect Permission Assignment Privilege Escalation Vulnerability

ZDI-21-1077
ZDI-CAN-14603

CVE ID CVE-2021-26434
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 Visual Studio
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of Microsoft Visual Studio. 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 Visual Studio installer. The issue results from incorrect permissions set on a resource used by the installer. 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-2021-26434
DISCLOSURE TIMELINE
  • 2021-07-13 - Vulnerability reported to vendor
  • 2021-09-16 - Coordinated public release of advisory
CREDIT Michael DePlante (@izobashi) of Trend Micro's Zero Day Initiative
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