Monthly Fallout Report

January 2025 Fallout

159 vulnerabilities, 3 Hyper-V zero-days, and Kerberos throwing tantrums. Classic start to the year.

Damage Rating
159
Vulnerabilities
3
Zero-Days
3
Critical RCEs
2
KB Updates

Fallout Timeline

Initial Release — Patch Tuesday Day 0

Vault dwellers, January 2025 hits hard with 159 vulnerabilities — including 3 critical Hyper-V zero-days that could hand attackers elevated privileges on virtualized systems. Three additional CVEs have functional exploit code in the wild, so the clock is ticking. Windows 10 (KB5049981) and Windows 11 (KB5050009) updates are the priority. Patch now — especially if you run Hyper-V!

CVE-2025-21333 CVSS 7.8

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege — actively exploited.

CVE-2025-21334 CVSS 7.8

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege — actively exploited.

CVE-2025-21335 CVSS 7.8

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege — actively exploited.

Sources: r/sysadmin · BleepingComputer · MSRC

72 Hours Out +3 Days Issues Active

Three days in and the wasteland is rumbling. BSOD crashes are gate-crashing the party — Kerberos and the Local Security Authority Process decided to throw tantrums, and the System Guard Runtime Monitor Broker Service (SgrmBroker.exe) apparently took a post-update nap. Microsoft Teams is vanishing from Windows 11 startups. Hyper-V Domain Controllers are rebooting due to authentication bugs. Classic January chaos.

Sources: r/sysadmin · WZorNET

2 Weeks Out +14 Days Largely Resolved

Two weeks out, things have largely stabilized. Microsoft confirmed that SgrmBroker.exe has been effectively deprecated for years and poses no active security risk. A handful of lingering issues remain across specific configurations — check the items below if you're still seeing problems.

Sources: r/sysadmin

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