CVE-2025-60704: Elevation of Privilege via Missing Cryptographic Step in Windows Kerberos S4U (CheckSum) Vulnerability ID: CVE-2025-60704 CVSS Score: 7.5 Published: 2025-11-11 CVE-2025-60704 is a critical elevation of privilege vulnerability in the Windows Kerberos authentication protocol. The flaw resides in the handling of Service for User (S4U) extensions, specifically within the protocol transition logic. A missing cryptographic step allows attackers to bypass checksum validation in the PA-S4U-X509-USER structure, leading to unauthorized identity impersonation and domain compromise. TL;DR A flaw in Windows Kerberos KDC allows attackers to bypass keyed checksum validation in S4U2self requests. By downgrading the checksum, an attacker can forge a user identity and obtain service tickets, leading to privilege escalation in environments using Constrained Delegation.…