CVE-2024-30039 is a medium-severity vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) affecting the Remote Access Connection Manager component. The vulnerability is classified as a buffer over-read (CWE-126), which occurs when the software reads more data than the buffer allocated, potentially leading to information disclosure. Specifically, this flaw allows an attacker with limited privileges (requires local access and low privileges) to cause the Remote Access Connection Manager to read beyond the intended memory boundaries. This can result in the exposure of sensitive information from memory, compromising confidentiality. The vulnerability does not affect system integrity or availability, as it does not allow code execution or denial of service. Exploitation does not require user interaction but does require local access and low privileges, which limits the attack vector primarily to local or insider threats. The CVSS v3.1 base score is 5.5, reflecting a medium severity level, with the attack vector being local (AV:L), low attack complexity (AC:L), and requiring privileges (PR:L). No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may rely on general security best practices until an official fix is released. The vulnerability is related to CWE-126 (Buffer Over-read) and CWE-125 (Out-of-bounds Read), both indicating improper memory handling that can lead to information leakage.

For European organizations, the primary impact of CVE-2024-30039 is the potential unauthorized disclosure of sensitive information residing in memory of systems running Windows 10 Version 1809. This version, although superseded by newer releases, remains in use in some legacy environments, particularly in industrial control systems, government agencies, and enterprises with strict change management policies. Information disclosure can facilitate further attacks by revealing credentials, cryptographic keys, or other sensitive data. Since exploitation requires local access and low privileges, the risk is heightened in environments where insider threats or compromised user accounts exist. Confidentiality breaches could lead to exposure of personal data protected under GDPR, resulting in regulatory penalties and reputational damage. The vulnerability does not allow for remote exploitation or denial of service, so the broader network impact is limited. However, targeted attacks against critical infrastructure or sensitive government systems using legacy Windows 10 1809 installations could leverage this flaw to escalate privileges or gather intelligence. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits over time.

1. Upgrade affected systems: The most effective mitigation is to upgrade Windows 10 Version 1809 systems to a supported, patched version of Windows 10 or Windows 11 where this vulnerability is addressed. 2. Restrict local access: Limit local user access to systems running Windows 10 1809, especially in sensitive environments, to reduce the risk of exploitation by low-privilege users. 3. Implement strict privilege management: Enforce the principle of least privilege to minimize the number of users with local access and low privileges on critical systems. 4. Monitor for suspicious activity: Deploy endpoint detection and response (EDR) solutions to detect unusual access patterns or attempts to exploit local vulnerabilities. 5. Network segmentation: Isolate legacy systems running Windows 10 1809 from general user networks to reduce the likelihood of insider threats or lateral movement. 6. Prepare for patch deployment: Monitor Microsoft security advisories for the release of an official patch and plan timely deployment once available. 7. Conduct regular audits: Review and audit user accounts and permissions on affected systems to identify and remove unnecessary local accounts. These steps go beyond generic advice by focusing on controlling local access and privilege management specific to the attack vector and affected Windows version.