VulnerabilityAnalyzed
CVE-2025-33073
Microsoft Windows SMB Client Improper Access Control Vulnerability
KEVHIGH 8.8EPSS 82.7%
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 10 November 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
Improper access control in Windows SMB allows an authorized attacker to elevate privileges over a network.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 82.70% probability · 100th percentile
- CISA KEV
- Listed 20 October 2025 · due 10 November 2025
- Weakness
- CWE-284
- Affected
- microsoft/windows 10 1507 · microsoft/windows 10 1607 · microsoft/windows 10 1809 · microsoft/windows 10 21h2 · microsoft/windows 10 22h2 · microsoft/windows 11 22h2 · microsoft/windows 11 23h2 · microsoft/windows 11 24h2 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019 · microsoft/windows server 2022 · microsoft/windows server 2022 23h2 · microsoft/windows server 2025
- Source
- secure@microsoft.com
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2025-33073 ; https://nvd.nist.gov/vuln/detail/CVE-2025-33073
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-33073Vendor Advisory
- https://www.vicarius.io/vsociety/posts/cve-2025-33073-detection-script-improper-access-control-in-windows-smb-affects-microsoft-productsThird Party Advisory
- https://www.vicarius.io/vsociety/posts/cve-2025-33073-mitigation-script-improper-access-control-in-windows-smb-affects-microsoft-productsMitigation, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-33073US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.