CVE-2025-29958 is a vulnerability identified in Microsoft Windows 10 Version 1809, specifically affecting the Windows Routing and Remote Access Service (RRAS). The issue is classified under CWE-908, which pertains to the use of uninitialized resources. In this context, the vulnerability arises because RRAS improperly handles certain resources without initializing them first. This flaw can be exploited by an unauthorized attacker over a network to disclose sensitive information. The vulnerability does not require any privileges (PR:N) but does require user interaction (UI:R), meaning the attacker must trick a user into performing some action, such as connecting to a malicious network or service. The attack vector is network-based (AV:N), and the vulnerability impacts confidentiality (C:H) but does not affect integrity or availability. The scope remains unchanged (S:U), indicating the vulnerability affects only the vulnerable component and does not propagate to other system components. The CVSS v3.1 base score is 6.5, categorizing it as a medium severity vulnerability. No known exploits are currently in the wild, and no patches have been linked yet. The vulnerability was reserved in March 2025 and published in May 2025, indicating recent discovery and disclosure. The technical root cause is the use of uninitialized resources in RRAS, which can lead to unintended information leakage over the network, potentially exposing sensitive data to attackers who can intercept or manipulate network traffic or induce user interaction to trigger the flaw.

For European organizations, this vulnerability poses a moderate risk primarily to systems running Windows 10 Version 1809 with RRAS enabled. RRAS is commonly used to provide VPN, routing, and remote access capabilities, which are critical for secure remote connectivity. Exploitation could lead to unauthorized disclosure of sensitive information, such as configuration details or network traffic metadata, which attackers could leverage for further attacks or espionage. Given the medium severity and the requirement for user interaction, the threat is more pronounced in environments where users frequently connect to untrusted networks or where social engineering is plausible. Industries with high reliance on remote access, such as finance, healthcare, and government sectors, may face increased risk. Additionally, organizations that have not updated or migrated from Windows 10 Version 1809 are more vulnerable, as newer Windows versions may have addressed this issue. The lack of known exploits reduces immediate risk, but the potential for information leakage could facilitate more sophisticated attacks if leveraged by threat actors targeting European entities.

To mitigate this vulnerability effectively, European organizations should: 1) Prioritize upgrading or patching Windows 10 systems, especially those running Version 1809 with RRAS enabled, as soon as official patches become available from Microsoft. 2) Disable RRAS on systems where it is not strictly necessary to reduce the attack surface. 3) Implement strict network segmentation and access controls to limit exposure of RRAS services to untrusted networks. 4) Educate users about the risks of connecting to unknown or untrusted networks and the importance of cautious interaction with network prompts to reduce the likelihood of triggering the vulnerability. 5) Monitor network traffic for unusual patterns that could indicate attempts to exploit RRAS-related vulnerabilities. 6) Employ endpoint detection and response (EDR) tools capable of identifying anomalous RRAS behavior or exploitation attempts. 7) Maintain an inventory of systems running Windows 10 Version 1809 and plan for timely upgrades to supported Windows versions with improved security postures.