CVE-2025-53798 is a buffer over-read vulnerability classified under CWE-126, affecting the Windows Routing and Remote Access Service (RRAS) component in Microsoft Windows Server 2019 (build 10.0.17763.0). The flaw arises from improper bounds checking during processing of network packets, which allows an attacker to read beyond the intended buffer limits. This can lead to disclosure of sensitive information residing in adjacent memory areas. The vulnerability is exploitable remotely over the network without requiring any privileges, though it does require user interaction, such as triggering a specific network request or connection attempt to the RRAS service. The CVSS v3.1 base score is 6.5 (medium severity), reflecting the high confidentiality impact but no impact on integrity or availability. The attack vector is network-based (AV:N), with low attack complexity (AC:L), no privileges required (PR:N), and user interaction required (UI:R). The scope remains unchanged (S:U), meaning the vulnerability affects only the vulnerable component. No known exploits have been reported in the wild, and no patches have been published at the time of analysis. RRAS is commonly used for VPN and routing services, so systems with this service enabled and exposed to untrusted networks are at risk. The vulnerability could allow attackers to glean sensitive information that might facilitate further attacks or reconnaissance.

For European organizations, this vulnerability poses a risk of sensitive information disclosure from Windows Server 2019 systems running RRAS, potentially exposing internal network details, configuration data, or other memory-resident information. This could aid attackers in mapping networks, escalating privileges, or crafting targeted attacks. Organizations in sectors such as government, finance, telecommunications, and critical infrastructure that rely on RRAS for remote access or routing services are particularly at risk. The confidentiality breach could undermine compliance with data protection regulations such as GDPR, especially if personal or sensitive data is exposed. While the vulnerability does not directly impact system integrity or availability, the information leakage could be leveraged for subsequent attacks, increasing overall risk. The requirement for user interaction somewhat limits exploitation but does not eliminate risk, especially in environments with automated or unattended network interactions. The absence of known exploits currently provides a window for proactive mitigation.

European organizations should immediately assess the deployment of RRAS on Windows Server 2019 systems and evaluate exposure to untrusted networks. If RRAS is not essential, it should be disabled to eliminate the attack surface. Network segmentation and firewall rules should be applied to restrict access to RRAS services only to trusted hosts and networks. Monitoring network traffic for unusual or malformed packets targeting RRAS can help detect attempted exploitation. Organizations should prepare for rapid deployment of official patches once Microsoft releases them and test updates in controlled environments before production rollout. Additionally, applying the principle of least privilege and ensuring that servers are not unnecessarily exposed to the internet will reduce risk. Security teams should update incident response plans to include this vulnerability and educate users about potential phishing or social engineering attempts that could trigger the required user interaction. Finally, maintaining up-to-date backups and system inventories will aid in recovery and impact assessment if exploitation occurs.