CVE-2025-24056 is a high-severity heap-based buffer overflow vulnerability identified in Microsoft Windows 10 Version 1809, specifically affecting the Windows Telephony Server component. This vulnerability, classified under CWE-122, allows an unauthorized attacker to remotely execute arbitrary code over a network without requiring prior authentication, though user interaction is needed. The flaw arises from improper handling of memory buffers in the Telephony Server, which can be exploited by sending specially crafted network packets to the vulnerable system. Successful exploitation can lead to full compromise of the affected system, impacting confidentiality, integrity, and availability. The CVSS v3.1 base score of 8.8 reflects the critical nature of this vulnerability, with network attack vector, low attack complexity, no privileges required, and high impact on all security properties. Although no known exploits are currently reported in the wild, the presence of this vulnerability in a widely deployed Windows version makes it a significant risk. The lack of available patches at the time of publication increases the urgency for mitigation and monitoring.

For European organizations, the impact of CVE-2025-24056 could be substantial, especially for those still operating legacy systems running Windows 10 Version 1809. The ability for an unauthenticated attacker to remotely execute code means that critical infrastructure, enterprise networks, and telephony-related services could be compromised, leading to data breaches, service disruptions, and potential lateral movement within networks. Given the high confidentiality, integrity, and availability impacts, sensitive data could be exfiltrated or manipulated, and systems could be rendered inoperable. Organizations in sectors such as telecommunications, finance, healthcare, and government are particularly at risk due to their reliance on telephony services and the critical nature of their operations. The requirement for user interaction slightly reduces the risk but does not eliminate it, as social engineering or automated triggers could facilitate exploitation. The absence of patches necessitates immediate risk management to prevent exploitation.

European organizations should implement a multi-layered mitigation approach beyond generic patching advice. First, identify and inventory all systems running Windows 10 Version 1809, prioritizing those exposing Telephony Server services to untrusted networks. Network segmentation should be enforced to isolate vulnerable systems and restrict access to telephony-related services. Deploy intrusion detection and prevention systems (IDS/IPS) with updated signatures to detect anomalous traffic patterns targeting the Telephony Server. Employ application whitelisting and endpoint protection solutions capable of detecting exploitation attempts. Since no patches are currently available, consider disabling or restricting the Telephony Server service where feasible, especially on systems not requiring telephony functionality. Implement strict user awareness training to reduce the risk of user interaction exploitation vectors. Monitor security advisories closely for patch releases and apply them promptly once available. Additionally, conduct regular vulnerability scans and penetration tests to assess exposure and effectiveness of mitigations.