CVE-2020-0951: Windows Defender Application Control Security Feature Bypass Vulnerability

Overview

Severity

Medium (CVSS 6.7)

CVSS Vector

CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2020-Sep

Released

2020-09-08

Last Updated

2021-10-14

EPSS Score

0.53% (percentile: 67.4%)

Description

A security feature bypass vulnerability exists in Windows Defender Application Control (WDAC) which could allow an attacker to bypass WDAC enforcement. An attacker who successfully exploited this vulnerability could execute PowerShell commands that would be blocked by WDAC. To exploit the vulnerability, an attacker need administrator access on a local machine where PowerShell is running. The attacker could then connect to a PowerShell session and send commands to execute arbitrary code. The update addresses the vulnerability by correcting how PowerShell commands are validated when WDAC protection is enabled.

Affected Products (29)

Other

• 11497
• 11498
• 11563
• 11568
• 11569
• 11570
• 11571
• 11572
• 11712
• 11713
• 11714
• 11715
• 11453
• 11454
• 11583
• 11644
• 11645
• 11646
• 11647
• 11766
• 11767
• 11768
• 11769
• 10852
• 10853
• 10816
• 10855
• 11745
• 11925

Security Updates (7)

• 4577032
• 4570333
• 4574727
• 4577041
• 4571756
• 4577015
• Release Notes

Acknowledgments

Paul Higinbotham

Revision History

• 2020-09-08: Information published.
• 2021-10-14: Revised the Security Updates table to include PowerShell 7.0 and PowerShell 7.1 because these versions of PowerShell 7 are affected by this vulnerability. See https://github.com/PowerShell/Announcements/issues/27 for more information.