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Full vulnerability report · 2023
CVE-2023-21771High confidence

Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability

Microsoft · Windows Server 2022

7.0HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2023-25938

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability

What

Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability

Why

The product stores sensitive data in memory that is not locked, or that has been incorrectly locked, which might cause the memory to be written to swap files on disk by the virtual memory manager. This can make the data more accessible to external actors.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability

Why

The product stores sensitive data in memory that is not locked, or that has been incorrectly locked, which might cause the memory to be written to swap files on disk by the virtual memory manager. This can make the data more accessible to external actors.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Sensitive Data Storage in Improperly Locked Memory → gain additional privileges
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-591 ↗

CWE-591: Sensitive Data Storage in Improperly Locked Memory. The product stores sensitive data in memory that is not locked, or that has been incorrectly locked, which might cause the memory to be written to swap files on disk by the virtual memory manager. This can make the data more accessible to external actors.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
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

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Privilege escalationCWE-591
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2023-0055Microsoft Windows und Microsoft Windows Server: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows und Microsoft Windows Server ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, seine Privilegien zu erweitern und einen Denial-of-Service-Zustand auszulösen.

Official advisory
CERT-FR · French · CERTFR-2023-AVI-0022Multiples vulnérabilités dans Microsoft Windows

janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21760 Bulletin de sécurité Microsoft CVE-2023-21765 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21765 Bulletin de sécurité Microsoft CVE-2023-21766 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21766 Bulletin de sécurité Microsoft CVE-2023-21767 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21767 Bulletin de sécurité Microsoft CVE-2023-21768 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21768 Bulletin de sécurité Microsoft CVE-2023-21771 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21771 Bulletin de sécurité Microsoft CVE-2023-21772 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21772 Bulletin de sécurité Microsoft CVE-2023-21773 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21773 Bulletin de sécurité Microsoft CVE-2023-21774 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21774 Bulletin de sécurité Microsoft CVE-2023-21776 du 10 janvier 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21776 Référence CVE CVE-2023-21

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
10.0.20348.0 < 10.0.20348.1487; 10.0.0 < 10.0.19042.2486; 10.0.0 < 10.0.22000.1455; 10.0.19043.0 < 10.0.19044.2486; 10.0.22621.0 < 10.0.22621.1105; 10.0.19045.0 < 10.0.19045.2486
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 10 Jan 2023 · Last source change 12 Apr 2025, 03:55 UTC · CWE-591 · Sensitive Data Storage in Improperly Locked Memory

CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2023-25938
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceOther authority
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2023-25938↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2023-21771 · cve.blacktree.nl