CVE-2023-21547
Published: 10 January 2023
Summary
CVE-2023-21547 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Microsoft Windows 10 1809. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 10.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
CVE-2023-21547 is a denial-of-service vulnerability in the Internet Key Exchange (IKE) protocol implementation, carrying a CVSS 3.1 score of 7.5. The flaw is associated with CWE-476 and CWE-400 and permits remote, unauthenticated attackers to trigger crashes or resource exhaustion that render affected systems unavailable.
An attacker with network access can send specially crafted IKE traffic to exploit the issue, achieving denial of service without any user interaction or elevated privileges. The attack requires no authentication and targets the availability of the IKE service directly.
Microsoft’s security advisory at msrc.microsoft.com details the affected components and supplies patches; administrators should apply the updates referenced in the guidance to eliminate the exposure.
EPSS for the CVE rose from a low baseline to a recorded peak of 0.0685 on 2025-12-11 before receding to the current value of 0.0444, indicating a measurable increase in exploitation interest after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-25714
Vulnerability details
Internet Key Exchange (IKE) Protocol Denial of Service Vulnerability
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
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.
Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.
Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.
Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.
Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.
Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.
Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.
The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.
Timely maintenance support and spare parts enable rapid recovery from failures induced by uncontrolled resource consumption, shortening the impact window of denial-of-service attacks.