CVE-2025-4540 is a critical security vulnerability identified in MTSoftware's C-Lodop version 6.6.1.1, specifically affecting the Windows platform. The vulnerability arises from an unquoted search path issue within the CLodopPrintService component. Unquoted search path vulnerabilities occur when the system searches for executable files in directories that are not properly quoted, allowing an attacker to place a malicious executable in a higher-priority directory. When the service or application attempts to execute a legitimate file, it may inadvertently run the attacker's code instead. This particular vulnerability requires local access to the affected system, meaning an attacker must have some level of access or presence on the machine to exploit it. The attack complexity is rated as high, indicating that exploitation is not straightforward and may require advanced skills or specific conditions. No user interaction is needed once local access is obtained, and the vulnerability impacts confidentiality, integrity, and availability at a high level. The CVSS 4.0 base score is 7.3, reflecting a high severity level. The vulnerability does not require authentication but does require local privileges, and the scope is limited to the affected component without privilege escalation beyond the local system. Although public exploit code has been disclosed, there are no known widespread exploits in the wild at this time. The vendor has addressed the issue in version 6.6.13, and upgrading to this or later versions is recommended to mitigate the risk. The vulnerability's presence in a printing service component suggests potential risks in environments where C-Lodop is used for print management or document processing, possibly affecting automated workflows or sensitive document handling.

For European organizations, the impact of CVE-2025-4540 can be significant, especially in sectors relying heavily on printing services integrated with C-Lodop, such as government agencies, financial institutions, healthcare providers, and large enterprises. Exploitation could allow an attacker with local access to execute arbitrary code with the privileges of the CLodopPrintService, potentially leading to unauthorized data access, modification, or disruption of printing services. This could result in leakage of sensitive information, disruption of business-critical document workflows, or serve as a foothold for further lateral movement within the network. Given the high complexity and local access requirement, the threat is more relevant in environments where insider threats or compromised endpoints are a concern. The availability of a public exploit increases the urgency for patching, as attackers may develop more accessible attack methods over time. Organizations with distributed printing infrastructure or remote desktop environments where local access can be obtained remotely are particularly at risk. Failure to address this vulnerability could lead to operational disruptions and compliance issues under European data protection regulations if sensitive data is exposed or integrity compromised.

To mitigate CVE-2025-4540, European organizations should prioritize upgrading the affected C-Lodop component to version 6.6.13 or later, as this update resolves the unquoted search path vulnerability. Beyond patching, organizations should implement strict local access controls to limit the number of users and processes that can interact with the CLodopPrintService. Employ application whitelisting and endpoint protection solutions to detect and prevent unauthorized executable files from being placed in directories searched by the service. Conduct regular audits of the system PATH environment variables and service configurations to ensure no unquoted paths exist. Additionally, restrict write permissions on directories involved in the search path to prevent malicious file placement. Network segmentation and the use of least privilege principles for user accounts can reduce the risk of local exploitation. Monitoring and logging of local service activities should be enhanced to detect suspicious behavior indicative of exploitation attempts. Finally, educate IT staff and users about the risks of local privilege abuse and maintain an incident response plan tailored to address local exploitation scenarios.