Description

Time-of-check time-of-use (toctou) race condition in Windows Local Security Authority (LSA) allows an authorized attacker to elevate privileges locally.

Classification

CVE ID: CVE-2025-21191

CVSS Base Severity: HIGH

CVSS Base Score: 7.0

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Affected Products

Vendor: Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft, Microsoft

Product: Windows Server 2025, Windows Server 2025 (Server Core installation), Windows 10 Version 1809, Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows 10 Version 21H2, Windows 11 version 22H2, Windows 10 Version 22H2, Windows 11 version 22H3, Windows 11 Version 23H2, Windows Server 2022, 23H2 Edition (Server Core installation), Windows 11 Version 24H2, Windows 10 Version 1507, Windows 10 Version 1607, Windows Server 2016, Windows Server 2016 (Server Core installation), Windows Server 2008 Service Pack 2, Windows Server 2008 Service Pack 2 (Server Core installation), Windows Server 2008 Service Pack 2, Windows Server 2008 R2 Service Pack 1, Windows Server 2008 R2 Service Pack 1 (Server Core installation), Windows Server 2012, Windows Server 2012 (Server Core installation), Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation)

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 7.52% (scored less or equal to compared to others)

EPSS Date: 2025-04-18 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-21191
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21191

Timeline