CVE-2023-21757
Memory Safety in Microsoft Windows 10 1607 … 22h2
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2023-21757 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 21% 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.
Windows Layer 2 Tunneling Protocol (L2TP) in affected Windows versions contains a denial-of-service vulnerability tracked as CVE-2023-21757. The flaw, assigned CVSS 7.5 and linked to CWE-476, allows an unauthenticated network attacker to trigger a crash that renders the L2TP service unavailable while leaving confidentiality and integrity unaffected.
An adversary positioned on the network can send specially crafted L2TP traffic to exploit the issue without credentials or user interaction. Successful exploitation results in a high-impact availability condition that disrupts VPN connectivity for users relying on the protocol.
Microsoft’s Security Response Center advisory at the referenced URL supplies the official patch and any interim configuration guidance for administrators.
EPSS for the CVE reached a peak of 0.2395 after disclosure before settling at the current value of 0.1911, indicating measurable post-release exploitation interest that warrants renewed attention.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-25924
Vulnerability Data
Windows Layer 2 Tunneling Protocol (L2TP) Denial of Service Vulnerability
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
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.
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.
Security testing can detect NULL dereference defects before release.
Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.
Application security requirements can specify input validation and pointer-safety rules.
Secure architecture principles encourage defensive design that avoids unsafe pointer use.
Secure coding standards directly require NULL-pointer checks and safe dereference patterns.