CVE-2024-21427: Windows Kerberos Security Feature Bypass Vulnerability

Overview

Severity

High (CVSS 7.5)

CVSS Vector

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

Category

Security Feature Bypass

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2024-Mar

Released

2024-03-12

Last Updated

2024-04-25

EPSS Score

1.82% (percentile: 82.9%)

FAQ

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to gather information specific to the environment and take additional actions prior to exploitation to prepare the target environment. What kind of security feature could be bypassed by successfully exploiting this vulnerability? The authentication feature could be bypassed as this vulnerability allows impersonation.

Affected Products (9)

Windows

• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows Server 2016
• Windows Server 2016 (Server Core installation)

ESU

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

Security Updates (6)

• 5036896
• 5036909
• 5035959
• 5036910
• 5036899
• 5036960

Acknowledgments

Jo Sutton with Catalyst IT, <a href="https://twitter.com/4ndr3w6s">Andrew Schwartz</a> with <a href="https://www.trustedsec.com/">TrustedSec</a> and <a href="https://twitter.com/exploitph">Charlie Clark</a>

Revision History

• 2024-03-12: Information published.
• 2024-04-09: The following changes have been made: 1) In the Security Updates table, removed all supported client versions of Windows 10 and Windows 11 as they are not affected by this vulnerability. 2) To comprehensively address CVE-2024-21427 Microsoft has released April 2024 security updates for all affected versions of Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2022, 23H2 Edition. Microsoft strongly recommends that customers install the updates to be fully protected from the vulnerability. Customers whose systems are configured to receive automatic updates do not need to take any further action.
• 2024-04-25: Updated acknowledgment. This is an informational change only.