CVE-2014-6324
HIGHCVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
5Tags
Description
The Kerberos Key Distribution Center (KDC) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, and Windows Server 2012 Gold and R2 allows remote authenticated domain users to obtain domain administrator privileges via a forged signature in a ticket, as exploited in the wild in November 2014, aka "Kerberos Checksum Vulnerability."
Analysis
The Windows Kerberos KDC fails to properly validate PAC signatures, allowing any authenticated domain user to forge Kerberos tickets and gain domain administrator privileges. Known as MS14-068, one of the most critical Active Directory vulnerabilities ever disclosed.
Technical Context
The KDC accepts PAC signatures using any checksum algorithm, including weak MD5 (instead of requiring the server's keyed checksum). An authenticated user can request a TGT without a PAC, then generate a forged PAC claiming domain admin membership, sign it with MD5, and present it to the KDC, which incorrectly validates it.
Affected Products
['Microsoft Windows Server 2003 SP2', 'Microsoft Windows Server 2008 SP2/R2 SP1', 'Microsoft Windows Server 2012/R2', 'All Active Directory domain controllers running affected versions']
Remediation
Apply Microsoft security update MS14-068 immediately to ALL domain controllers. Audit domain admin group membership for unauthorized additions. Check Kerberos event logs for anomalous TGT requests. Consider enabling PAC validation checks.
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External POC / Exploit Code
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