CVE-2023-21771 | Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability

Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability

Published: 2023-01-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-21771 is rated Moderate Risk (48.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.39%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-21771

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-07 0.46% 0.39% -0.07%
2 2026-02-16 0.26% 0.46% +0.21%
3 2026-01-13 0.26%

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-21771

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.0 5.9 [email protected]

Weakness enumeration for CVE-2023-21771

Affected software / configurations for CVE-2023-21771

Vendor Product Version Raw CPE
microsoft windows_10 20h2 cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:*
microsoft windows_10 21h2 cpe:2.3:o:microsoft:windows_10:21h2:*:*:*:*:*:*:*
microsoft windows_10 22h2 cpe:2.3:o:microsoft:windows_10:22h2:*:*:*:*:*:*:*
microsoft windows_11 21h2 cpe:2.3:o:microsoft:windows_11:21h2:*:*:*:*:*:arm64:*
microsoft windows_11 21h2 cpe:2.3:o:microsoft:windows_11:21h2:*:*:*:*:*:x64:*
microsoft windows_11 22h2 cpe:2.3:o:microsoft:windows_11:22h2:*:*:*:*:*:arm64:*
microsoft windows_11 22h2 cpe:2.3:o:microsoft:windows_11:22h2:*:*:*:*:*:x64:*
microsoft windows_server_2022 cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:*

References for CVE-2023-21771

cvelogic Threat Intelligence