CVE-2023-21549: Windows SMB Witness Service Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 8.8)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Publicly Disclosed

Yes

Patch Tuesday

2023-Jan

Released

2023-01-10

Last Updated

2023-01-23

EPSS Score

7.02% (percentile: 91.5%)

FAQ

How could an attacker exploit the vulnerability? To exploit this vulnerability, an attacker could execute a specially crafted malicious script which executes an RPC call to an RPC host. This could result in elevation of privilege on the server. What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker who successfully exploited this vulnerability could execute RPC functions that are restricted to privileged accounts only.

Affected Products (32)

Windows

• Windows 10 Version 1809 for 32-bit Systems
• Windows 10 Version 1809 for x64-based Systems
• Windows 10 Version 1809 for ARM64-based Systems
• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows 10 Version 20H2 for 32-bit Systems
• Windows 10 Version 20H2 for ARM64-based Systems
• Windows 11 version 21H2 for x64-based Systems
• Windows 11 version 21H2 for ARM64-based Systems
• Windows 10 Version 21H2 for 32-bit Systems
• Windows 10 Version 21H2 for ARM64-based Systems
• Windows 10 Version 21H2 for x64-based Systems
• Windows 11 Version 22H2 for ARM64-based Systems
• Windows 11 Version 22H2 for x64-based Systems
• Windows 10 Version 22H2 for x64-based Systems
• Windows 10 Version 22H2 for ARM64-based Systems
• Windows 10 Version 22H2 for 32-bit Systems
• Windows 10 for 32-bit Systems
• Windows 10 for x64-based Systems
• Windows 10 Version 1607 for 32-bit Systems
• Windows 10 Version 1607 for x64-based Systems
• Windows Server 2016
• Windows Server 2016 (Server Core installation)
• Windows 8.1 for 32-bit systems
• Windows 8.1 for x64-based systems
• Windows RT 8.1

ESU

• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (11)

• 5022286
• 5022291
• 5022282
• 5022287
• 5022303
• 5022297
• 5022289
• 5022352
• 5022346
• 5022348
• 5022343

Acknowledgments

<a href="https://twitter.com/kupsul">Stiv Kupchik</a> and <a href=" https://twitter.com/OphirHarpaz">Ophir Harpaz</a> with Akamai

Revision History

• 2023-01-10: Information published.
• 2023-01-17: Updated CVE Tag. This is an informational change only.
• 2023-01-23: Revised the Security Updates table to include Windows 8.1 for 32-bit systems because it is affected by CVE-2023-21524 and removed Windows 7 for 32-bit Systems Service Pack 1 as it is not affected. Microsoft recommends that customers running Windows 8.1 for 32-bit systems should install security update 5022338 to be protected from this vulnerability.