SB2025040919 - Multiple vulnerabilities in Microsoft Windows Local Security Authority (LSA)

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2025-21191)

The vulnerability allows a local user to compromise the target system.

The vulnerability exists due to a time-of-check, time-of-use (TOCTOU) race condition in Windows Local Security Authority (LSA). A local user can gain elevated privileges on the target system.

2) Heap-based buffer overflow (CVE-ID: CVE-2025-27478)

The vulnerability allows a local user to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in Windows Local Security Authority (LSA). A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system with elevated privileges.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21191
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-27478