CVE-2024-38067 is a vulnerability identified in the Windows Online Certificate Status Protocol (OCSP) server component of Microsoft Windows Server 2019, specifically version 10.0.17763.0. The flaw is categorized under CWE-400, which pertains to uncontrolled resource consumption. The vulnerability allows an unauthenticated attacker to send specially crafted requests to the OCSP server, causing it to consume excessive system resources such as CPU, memory, or network bandwidth. This resource exhaustion can lead to a denial of service (DoS) condition, rendering the OCSP service unavailable. Since OCSP servers are critical for validating the revocation status of digital certificates in real-time, their unavailability can disrupt secure communications and authentication processes that depend on certificate validation. The CVSS v3.1 base score is 7.5 (high), reflecting the network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact is limited to availability, with no direct compromise of confidentiality or integrity. No patches have been linked yet, and no active exploitation has been reported, but the vulnerability is publicly disclosed and should be addressed promptly. The vulnerability affects only Windows Server 2019 build 17763.0, which is widely deployed in enterprise environments for certificate services and PKI infrastructure.

For European organizations, the primary impact of CVE-2024-38067 is the potential disruption of certificate validation services due to OCSP server unavailability. This can affect secure communications, including HTTPS connections, VPN authentication, email encryption, and other PKI-dependent services. Critical infrastructure sectors such as finance, healthcare, government, and telecommunications that rely heavily on Windows Server 2019 for certificate services may experience service outages or degraded security posture. The denial of service could also be leveraged as part of a larger attack chain to cause operational disruptions. Although confidentiality and integrity are not directly impacted, the loss of availability can lead to cascading effects on business continuity and trust in digital identities. European organizations with strict compliance requirements around security and availability may face regulatory and reputational risks if OCSP services are disrupted.

Organizations should monitor Microsoft security advisories closely and apply patches or updates as soon as they become available for Windows Server 2019 OCSP components. In the interim, network-level mitigations such as rate limiting, traffic filtering, and anomaly detection should be implemented to restrict abnormal OCSP request volumes from untrusted sources. Deploying Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) with signatures targeting OCSP abuse can help mitigate exploitation attempts. Additionally, organizations should consider deploying redundant OCSP responders and load balancing to improve resilience against DoS attacks. Regularly auditing and monitoring OCSP server logs for unusual traffic patterns can provide early warning of exploitation attempts. Finally, reviewing and hardening the overall PKI infrastructure, including fallback mechanisms like CRL (Certificate Revocation Lists), can reduce reliance on a single OCSP server and improve availability.