CVE-2025-53153 is a vulnerability identified in Microsoft Windows Server 2019, specifically affecting the Routing and Remote Access Service (RRAS). The root cause is the use of an uninitialized resource, classified under CWE-908, which can lead to unintended information disclosure. This flaw allows an attacker who is authorized on the system (i.e., has some level of privileges) and can interact with the system over the network to potentially access sensitive information that should otherwise remain protected. The vulnerability does not allow for privilege escalation, code execution, or denial of service, but it compromises confidentiality by leaking data. The CVSS v3.1 base score is 5.7, indicating a medium severity level, with the vector string showing network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), and user interaction (UI:R). The scope remains unchanged (S:U), and the impact is high on confidentiality (C:H), none on integrity (I:N) and availability (A:N). No known exploits have been reported in the wild, and no patches have been linked yet, but the vulnerability is publicly disclosed and should be addressed promptly. The vulnerability could be exploited by an attacker who convinces a legitimate user to perform an action or by an insider with limited privileges, potentially exposing sensitive routing or remote access configuration or data over the network.

For European organizations, the primary impact is the potential unauthorized disclosure of sensitive information related to network routing and remote access configurations or data. This could lead to exposure of internal network topology, credentials, or other confidential information that attackers could leverage for further attacks such as lateral movement or targeted intrusions. Organizations in sectors such as finance, government, healthcare, and critical infrastructure that rely heavily on Windows Server 2019 and RRAS for secure remote connectivity are particularly vulnerable. The confidentiality breach could undermine compliance with GDPR and other data protection regulations, leading to legal and reputational consequences. Although the vulnerability does not directly affect system integrity or availability, the information disclosure could facilitate more severe attacks if combined with other vulnerabilities or social engineering tactics. The requirement for privileges and user interaction limits the attack surface but does not eliminate risk, especially in environments with many authorized users or exposed RRAS services.

1. Monitor Microsoft security advisories closely and apply official patches or updates for Windows Server 2019 RRAS as soon as they become available. 2. Restrict access to RRAS services to only trusted and necessary users and systems, employing network segmentation and firewall rules to limit exposure. 3. Enforce the principle of least privilege for all accounts with access to RRAS, minimizing the number of users who can interact with the vulnerable service. 4. Implement multi-factor authentication (MFA) for accounts authorized to use RRAS to reduce the risk of credential compromise. 5. Conduct regular audits and monitoring of RRAS logs and network traffic for unusual or unauthorized access patterns that could indicate exploitation attempts. 6. Educate users about the risks of social engineering and the importance of cautious interaction with network services requiring user input. 7. Consider disabling RRAS if it is not essential to the organization's operations or replacing it with alternative secure remote access solutions. 8. Maintain up-to-date backups and incident response plans to quickly respond to any potential breaches stemming from this vulnerability.