CVE-2021-33786: Windows LSA Security Feature Bypass Vulnerability

Overview

Severity

High (CVSS 8.1)

CVSS Vector

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

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2021-Jul

Released

2021-07-13

EPSS Score

1.53% (percentile: 81.3%)

FAQ

What kind of security feature could be bypassed by successfully exploiting this vulnerability? A read only domain controller (RODC) is able to delegate rights by granting itself a ticket. A full DC does not validate the ticket thus granting R/W privileges to a DC that should only have read privileges.

Affected Products (16)

Windows

• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server, version 2004 (Server Core installation)
• Windows Server, version 20H2 (Server Core Installation)
• Windows Server 2016
• Windows Server 2016 (Server Core installation)
• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

ESU

• Windows Server 2008 for 32-bit Systems Service Pack 2
• Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 for x64-based Systems Service Pack 2
• Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 R2 for x64-based Systems Service Pack 1
• Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)

Security Updates (11)

• 5004244
• 5004237
• 5004238
• 5004305
• 5004299
• 5004289
• 5004307
• 5004294
• 5004302
• 5004298
• 5004285

Revision History

• 2021-07-13: Information published.