CVE-2025-53797 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 vulnerability arises due to improper bounds checking within RRAS, which processes network packets. An attacker can exploit this flaw by sending specially crafted packets to a vulnerable server, causing the service to read beyond the intended buffer boundaries. This over-read can lead to disclosure of sensitive information residing in adjacent memory areas, potentially exposing confidential data over the network. The vulnerability does not allow modification of data or denial of service but compromises confidentiality. According to the CVSS v3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N), the attack can be performed remotely over the network without privileges but requires user interaction, such as the victim processing malicious packets. The scope remains unchanged, affecting only the vulnerable component. No known public exploits or patches are available at the time of publication, increasing the urgency for defensive measures. RRAS is commonly used for VPN and routing services, making this vulnerability relevant for organizations utilizing these features on Windows Server 2019.

For European organizations, the primary impact of CVE-2025-53797 is the unauthorized disclosure of sensitive information, which can include internal network details, configuration data, or other memory-resident secrets. This can facilitate further targeted attacks, espionage, or data leakage incidents. Organizations in sectors such as telecommunications, government, finance, and critical infrastructure that rely on RRAS for remote access or routing are particularly at risk. The vulnerability's remote exploitability without authentication increases the attack surface, especially if RRAS services are exposed to untrusted networks or the internet. Although no integrity or availability impact is present, the confidentiality breach can lead to regulatory non-compliance under GDPR and damage organizational reputation. The lack of known exploits reduces immediate risk but also means defenders must proactively mitigate before exploitation occurs.

1. Disable the Routing and Remote Access Service (RRAS) if it is not essential for business operations to eliminate the attack vector. 2. Restrict RRAS exposure by implementing strict firewall rules to limit access only to trusted internal networks or VPN endpoints. 3. Employ network segmentation to isolate servers running RRAS from general user and internet-facing networks. 4. Monitor network traffic for unusual or malformed packets targeting RRAS ports to detect potential exploitation attempts. 5. Apply principle of least privilege and ensure servers are hardened with up-to-date security configurations. 6. Stay alert for official patches or security advisories from Microsoft and apply updates promptly once available. 7. Conduct regular security assessments and penetration testing focusing on RRAS and related network services. 8. Educate network administrators about this vulnerability and the importance of minimizing RRAS exposure.