CVE-2025-24051 is a high-severity heap-based buffer overflow vulnerability identified in the Windows Routing and Remote Access Service (RRAS) component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises due to improper handling of memory allocations on the heap, which can be exploited by an unauthorized attacker remotely over the network. Specifically, an attacker can send specially crafted packets to the RRAS service, triggering the overflow condition. This overflow can lead to arbitrary code execution with system-level privileges, potentially allowing the attacker to fully compromise the affected system. The vulnerability does not require prior authentication (PR:N) but does require some user interaction (UI:R), such as the user initiating a connection or service interaction that triggers the vulnerable code path. The CVSS v3.1 base score is 8.8, reflecting high impact on confidentiality, integrity, and availability (all rated high). The attack vector is network-based (AV:N), with low attack complexity (AC:L), and the scope remains unchanged (S:U). No known exploits are currently observed in the wild, and no official patches have been linked yet, indicating that organizations must be vigilant and prepare for mitigation once patches are released. The vulnerability is categorized under CWE-122, which is a common weakness related to heap-based buffer overflows, a critical class of memory corruption bugs often leading to remote code execution.

For European organizations, this vulnerability poses a significant risk, especially for those still operating legacy systems running Windows 10 Version 1809, which is an older but still in-use version in many enterprises. Exploitation could lead to full system compromise, data breaches, disruption of critical network services, and lateral movement within corporate networks. Organizations relying on RRAS for VPN, remote access, or routing services are particularly vulnerable, as this service is exposed to network traffic and often accessible from untrusted networks or the internet. The high severity and remote exploitability mean attackers could leverage this flaw to gain unauthorized access without credentials, potentially impacting confidentiality of sensitive data, integrity of systems, and availability of network services. Given the geopolitical climate and increasing cyber espionage and ransomware activities targeting European infrastructure and enterprises, this vulnerability could be leveraged by threat actors to disrupt operations or exfiltrate data. The absence of known exploits in the wild currently provides a window for proactive defense, but the lack of an official patch at the time of this report necessitates immediate risk mitigation.

European organizations should immediately conduct an inventory to identify all systems running Windows 10 Version 1809 with RRAS enabled. Until a patch is released, network-level mitigations should be applied, including restricting access to RRAS services via firewall rules to trusted IP addresses only and disabling RRAS if it is not essential. Employ network segmentation to isolate vulnerable systems from critical infrastructure. Monitor network traffic for unusual or malformed packets targeting RRAS ports and enable enhanced logging and alerting for RRAS service anomalies. Organizations should also prepare for rapid deployment of patches once Microsoft releases them. Additionally, implement strict endpoint protection with behavior-based detection to identify exploitation attempts. User education to avoid initiating suspicious connections that could trigger the vulnerability is also recommended. Finally, consider upgrading affected systems to a supported, patched version of Windows where feasible to eliminate exposure.