CVE-2025-10198 is a high-severity vulnerability classified under CWE-427, which pertains to an Uncontrolled Search Path Element in the LizardByte Sunshine for Windows application, specifically version v2025.122.141614. This vulnerability arises from the way the application handles DLL search order on Windows systems. An attacker can exploit this by placing a malicious DLL in directories that are included in the user's PATH environment variable and are writable by the user. When the vulnerable application loads DLLs, it may inadvertently load the malicious DLL instead of the legitimate one due to the hijacked search path. This DLL search-order hijacking can lead to arbitrary code execution with the privileges of the user running the application. The CVSS v3.1 base score of 7.8 reflects a high severity, with the vector indicating that the attack requires local access (AV:L), low attack complexity (AC:L), no privileges required (PR:N), but requires user interaction (UI:R). The impact on confidentiality, integrity, and availability is high, as the attacker can execute arbitrary code, potentially leading to data theft, system compromise, or denial of service. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may rely on configuration changes or vendor updates once available. The vulnerability affects only the specified version of Sunshine for Windows, emphasizing the importance of version control and patch management.

For European organizations, this vulnerability poses a significant risk, especially in environments where Sunshine for Windows is deployed. Since the attack requires local access and user interaction, the threat is more pronounced in scenarios where users might be tricked into executing malicious files or visiting compromised locations that allow DLL planting. Successful exploitation could lead to unauthorized access to sensitive data, disruption of services, and potential lateral movement within corporate networks. Industries with high reliance on Windows-based remote access or streaming solutions, such as finance, healthcare, and critical infrastructure, could face operational disruptions and data breaches. Additionally, the ability to execute arbitrary code elevates the risk of deploying ransomware or other malware, which has been a growing concern in Europe. The lack of a patch at the time of disclosure necessitates immediate attention to reduce exposure, especially in regulated sectors bound by GDPR and other compliance frameworks where data breaches carry heavy penalties.

To mitigate this vulnerability effectively, European organizations should: 1) Restrict write permissions on directories included in the user PATH environment variable to prevent unauthorized DLL placement. 2) Employ application whitelisting and integrity verification mechanisms to detect and block unauthorized DLLs. 3) Educate users about the risks of executing untrusted files and the importance of cautious interaction with prompts or downloads. 4) Monitor and audit PATH environment variables and DLL loading behaviors using endpoint detection and response (EDR) tools to identify suspicious activity. 5) Isolate or sandbox the Sunshine for Windows application where feasible to limit the impact of potential exploitation. 6) Engage with LizardByte for updates or patches and plan for timely application once available. 7) Implement strict local user privilege management to minimize the impact of code execution under user context. These steps go beyond generic advice by focusing on environment hardening, user behavior, and proactive monitoring tailored to the nature of DLL hijacking.