CVE-2025-30397 is a vulnerability classified under CWE-843 (Access of Resource Using Incompatible Type, also known as type confusion) affecting Microsoft Windows 10 Version 1507 (build 10.0.10240.0). The flaw exists in the Microsoft Scripting Engine, a component responsible for executing scripts within the Windows environment. Type confusion occurs when the program accesses a resource using an incorrect or incompatible data type, which can lead to memory corruption. In this case, the vulnerability allows an unauthorized attacker to execute arbitrary code remotely over a network. The CVSS v3.1 score of 7.5 reflects a high severity, with attack vector being network-based (AV:N), requiring no privileges (PR:N), but requiring user interaction (UI:R) and high attack complexity (AC:H). The scope is unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). The exploitability is facilitated by the scripting engine's handling of data types, potentially allowing crafted scripts or network payloads to trigger the flaw. Although no known exploits have been reported in the wild, the vulnerability poses a significant risk due to the critical nature of remote code execution and the widespread use of Windows 10. The affected version, Windows 10 Version 1507, is an early release of Windows 10 and is largely out of support, increasing the risk for legacy systems. The vulnerability was reserved in March 2025 and published in May 2025, with no current patches available, emphasizing the need for mitigation through system upgrades and network defenses.

The potential impact of CVE-2025-30397 is severe for organizations still running Windows 10 Version 1507. Successful exploitation allows remote attackers to execute arbitrary code, potentially leading to full system compromise. This can result in unauthorized access to sensitive data (confidentiality breach), modification or destruction of data (integrity loss), and disruption of system operations (availability impact). Since the attack vector is network-based, attackers can target exposed systems remotely, increasing the risk to enterprise networks, especially those with legacy systems or insufficient network segmentation. The requirement for user interaction (e.g., opening a malicious script or link) somewhat limits exploitation but does not eliminate risk, particularly in environments with phishing or social engineering threats. The high attack complexity reduces the likelihood of widespread automated attacks but targeted attacks against high-value assets remain a concern. The lack of patches and the obsolescence of the affected Windows version exacerbate the risk, as organizations may be unable or unwilling to upgrade promptly. Overall, the vulnerability threatens critical infrastructure, government, financial institutions, and enterprises relying on legacy Windows 10 systems.

To mitigate CVE-2025-30397, organizations should prioritize upgrading affected systems from Windows 10 Version 1507 to a supported and patched Windows version, as no patches currently exist for this specific vulnerability. Implement network-level protections such as firewall rules to restrict inbound traffic to scripting engine-related services and employ intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious script execution or malformed network payloads. Enforce strict user privilege management and application whitelisting to limit the execution of unauthorized scripts. Enhance user awareness training to reduce the risk of social engineering and phishing attacks that could trigger the required user interaction for exploitation. Employ endpoint detection and response (EDR) solutions capable of detecting anomalous scripting engine behavior. Regularly audit and inventory legacy systems to identify and isolate vulnerable devices. Finally, monitor threat intelligence feeds for any emerging exploit code or patches related to this CVE to respond promptly.