Cyber Resilience

CVE-2025-33056

High

Published: 10 June 2025

Published
10 June 2025
Modified
10 July 2025
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0556 90.5th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-33056 is a high-severity Improper Access Control (CWE-284) vulnerability in Microsoft Windows Server 2008. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 9.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

The vulnerability CVE-2025-33056 stems from improper access control in the Microsoft Local Security Authority Server (lsasrv) component. It is tracked under CWE-284 and carries a CVSS 3.1 base score of 7.5 reflecting network attack vector, low complexity, and no required privileges or user interaction, with high impact limited to availability.

An unauthenticated attacker can send crafted network requests to trigger a denial-of-service condition against the affected lsasrv instance, disrupting authentication and security services on the target system without gaining code execution or data access.

Microsoft has published an advisory and associated guidance for this issue at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-33056. The current EPSS score of 0.0556 has shown no material increase since disclosure.

EU & UK References

Vulnerability details

Improper access control in Microsoft Local Security Authority Server (lsasrv) allows an unauthorized attacker to deny service over a network.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
windows 10 1507
≤ 10.0.10240.21034 · ≤ 10.0.10240.21034
microsoft
windows 10 1607
≤ 10.0.14393.8148 · ≤ 10.0.14393.8148
microsoft
windows 10 1809
≤ 10.0.17763.7434 · ≤ 10.0.17763.7434
microsoft
windows 10 21h2
≤ 10.0.19044.5965
microsoft
windows 10 22h2
≤ 10.0.19045.5965
microsoft
windows 11 22h2
≤ 10.0.22621.5472
microsoft
windows 11 23h2
≤ 10.0.22631.5472
microsoft
windows 11 24h2
≤ 10.0.26100.4270
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
+5 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-284

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284

Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.

addresses: CWE-284

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284

By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.

addresses: CWE-284

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

References