Microsoft Windows Kernel TOCTOU Race Condition Vulnerability
What it is
Microsoft Windows Kernel contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability that could allow for privilege escalation.
Known to be used in ransomware campaigns.Active threat actors have chained this vulnerability into ransomware operations — treat patching as a same-week priority, not a "next maintenance window" task. The coping action is the same one below; the urgency is higher.
Who's affected
Affects anyone running Windows workstations or servers. In a small CPA, legal, or dental practice, Windows is typically the platform your accounting, document management, or practice management software runs on — exploitation gives an attacker access to whatever client files and credentials live on those machines.
What to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA action deadline: November 5, 2024. Federal agencies must complete the required action by this date. For private SMBs the deadline is advisory — but treat it as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).
If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Book a free 20-minute triage call.
Severity
CVSS base score: 7.0 — HIGH
Weakness classification: CWE-367
Source
Pulled daily from the public cisagov/kev-data mirror (CC0). View the original entry on cisa.gov. CISA KEV is US-Government public-domain data; we add the SMB-vertical framing and the coping action above.