Cyber Resilience

CVE-2023-21758

Memory Safety in Microsoft Windows 10 1607 … 22h2

High EPSSMemory Safety
Published
10 January 2023
Modified
21 November 2024
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.93 99.8th percentile
Risk Priority 83 floored blend · peak EPSS

Summary

CVE-2023-21758 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Microsoft Windows 10. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 0.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability CVE-2023-21758 is a denial of service flaw in the Windows Internet Key Exchange (IKE) Extension, assigned a CVSS 3.1 base score of 7.5 with the vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H and linked to CWE-476. It affects the IKE component responsible for VPN and IPsec key negotiation on Windows systems.

An unauthenticated attacker with network access can send specially crafted traffic to trigger the flaw, resulting in a high-impact denial of service that disrupts IKE operations without affecting confidentiality or integrity.

Microsoft security advisories available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21758 describe the official patches and recommended mitigation actions for affected Windows versions.

The associated EPSS score rose from lower values after disclosure to a peak of 0.5296 on 2025-12-11 before receding to the current 0.4276, indicating a material increase in observed exploitation interest that warrants renewed attention.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Windows Internet Key Exchange (IKE) Extension Denial of Service Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-38072Same product: Microsoft Windows Server 2016
CVE-2023-21757Same product: Microsoft Windows 10
CVE-2023-24859Same product: Microsoft Windows 10
CVE-2026-21243Same product: Microsoft Windows Server 2019
CVE-2023-21700Same product: Microsoft Windows 10
CVE-2023-36709Same product: Microsoft Windows Server 2016
CVE-2023-32008Same product: Microsoft Windows Server 2016
CVE-2023-32084Same product: Microsoft Windows Server 2019
CVE-2026-57976Same product: Microsoft Windows Server 2016
CVE-2023-36602Same product: Microsoft Windows Server 2016

Affected Assets

microsoft
windows 10
1607, 1809, 20h2, 21h2, 22h2
microsoft
windows 11
21h2, 22h2, all versions
microsoft
windows server 2016
all versions
microsoft
windows server 2019
all versions
microsoft
windows server 2022
all versions

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References