CVE-2025-53798 is a buffer over-read vulnerability classified under CWE-126 affecting Microsoft Windows Server 2019, specifically version 10.0.17763.0. The flaw exists in the Windows Routing and Remote Access Service (RRAS), a component responsible for routing network traffic and providing remote access capabilities. A buffer over-read occurs when a program reads more data than the buffer it has allocated, potentially exposing sensitive memory contents. In this case, an unauthorized attacker can exploit this vulnerability remotely over the network without requiring privileges but does require user interaction, as indicated by the CVSS vector (UI:R). The vulnerability allows the attacker to disclose information, impacting confidentiality, but does not affect integrity or availability. The CVSS v3.1 base score is 6.5 (medium severity), reflecting the moderate impact and ease of exploitation (low attack complexity, no privileges required). No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability's scope is unchanged, meaning the impact is limited to the vulnerable component without affecting other system components. This vulnerability could be leveraged to gather sensitive information from the memory of the RRAS service, potentially aiding further attacks such as privilege escalation or lateral movement within a network.

For European organizations, this vulnerability poses a risk primarily to those using Windows Server 2019 with RRAS enabled, especially in environments relying on remote access and routing services. Disclosure of sensitive information could lead to exposure of credentials, configuration details, or other critical data that attackers can use to compromise network security further. Sectors with high reliance on secure remote access, such as finance, healthcare, and critical infrastructure, may face increased risks. While the vulnerability does not directly allow system compromise or denial of service, the information leak could facilitate more sophisticated attacks. Given the medium severity and lack of known exploits, the immediate risk is moderate; however, the potential for future exploitation means organizations should prioritize mitigation. The impact is heightened in environments where RRAS is exposed to untrusted networks or the internet, increasing the attack surface.

Organizations should first verify if Windows Server 2019 systems are running RRAS and assess exposure to untrusted networks. Until a patch is released, it is advisable to restrict RRAS access using network-level controls such as firewalls and VPNs to limit exposure. Monitoring network traffic for unusual activity targeting RRAS ports can help detect exploitation attempts. Applying the principle of least privilege by disabling RRAS if not required reduces the attack surface. Additionally, organizations should implement strict user interaction policies and educate users about the risks of interacting with unsolicited network prompts or connections related to RRAS. Once Microsoft releases a security update, prompt deployment is critical. Network segmentation and enhanced logging around RRAS services will aid in early detection and containment of potential exploitation.