CVE-2025-29954 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting Microsoft Windows 10 Version 1507 (build 10.0.10240.0). The flaw exists in the Lightweight Directory Access Protocol (LDAP) service implementation, where an attacker can send crafted network requests that cause the service 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 affected system or service unresponsive or degraded. The vulnerability is exploitable remotely over the network without requiring authentication or user interaction, increasing its risk profile. However, the attack complexity is rated high due to the need for specific crafted requests and conditions. The CVSS v3.1 base score is 5.9, reflecting a medium severity level primarily due to the impact on availability only, with no confidentiality or integrity compromise. No patches or fixes have been published at the time of disclosure, and there are no known exploits in the wild. The vulnerability was reserved in March 2025 and published in May 2025. It primarily affects legacy Windows 10 systems still running the initial release version 1507, which is largely out of mainstream support but may still be in use in some environments. The LDAP service is commonly used for directory services and authentication in enterprise networks, making this vulnerability relevant for organizations relying on Windows-based directory services.

For European organizations, the primary impact of CVE-2025-29954 is the potential for denial of service attacks against critical directory services that rely on LDAP in Windows 10 Version 1507 environments. This can disrupt authentication, access control, and other directory-dependent services, leading to operational downtime and productivity loss. Sectors such as government, finance, healthcare, and telecommunications that depend on legacy Windows infrastructure and LDAP for identity management are particularly vulnerable. The lack of confidentiality or integrity impact limits data breach risks, but availability degradation can have cascading effects on business continuity and incident response capabilities. Organizations with exposed LDAP endpoints or insufficient network segmentation face higher risks. The absence of known exploits reduces immediate threat but does not eliminate the risk of future exploitation, especially as attackers develop techniques to leverage this vulnerability.

1. Upgrade affected systems: Migrate from Windows 10 Version 1507 to a supported and patched Windows version to eliminate the vulnerability. 2. Network segmentation: Restrict LDAP traffic to trusted internal networks and block external access to LDAP ports (typically TCP/UDP 389 and 636). 3. Implement rate limiting and monitoring: Deploy network and host-based monitoring to detect unusual LDAP request patterns and resource usage spikes indicative of exploitation attempts. 4. Apply firewall rules: Use firewalls to limit LDAP traffic sources and destinations, reducing exposure to unauthorized actors. 5. Disable unnecessary LDAP services: If LDAP is not required on legacy systems, disable the service to remove the attack surface. 6. Incident response readiness: Prepare playbooks for DoS incidents affecting directory services to minimize downtime. 7. Stay updated: Monitor Microsoft advisories for patches or workarounds and apply them promptly once available.