CVE-2025-54100 is a command injection vulnerability classified under CWE-77, found in Microsoft Windows 10 Version 1809 (build 10.0.17763.0), specifically within Windows PowerShell. The flaw stems from improper neutralization of special characters or elements in command inputs, which allows an attacker with local access to craft malicious commands that the system executes without proper sanitization. This leads to arbitrary code execution with the privileges of the user running PowerShell. The vulnerability requires no privileges (PR:N) but does require user interaction (UI:R), such as convincing a user to run a crafted script or command. The attack vector is local (AV:L), meaning remote exploitation is not feasible without prior access. The vulnerability impacts confidentiality, integrity, and availability (all rated high), as an attacker can execute arbitrary code, potentially leading to data theft, system compromise, or denial of service. Although no known exploits are currently reported in the wild, the vulnerability is rated high severity with a CVSS 3.1 score of 7.8, indicating significant risk. The vulnerability was reserved in July 2025 and published in December 2025, with no patches currently linked, suggesting organizations must monitor for updates. This vulnerability is particularly concerning for environments that still operate Windows 10 Version 1809, which is an older release but may still be in use in legacy systems or specialized environments. The improper input validation in PowerShell commands highlights the need for strict command sanitization and user privilege management to prevent exploitation.

For European organizations, the impact of CVE-2025-54100 can be substantial, especially in sectors relying on legacy Windows 10 Version 1809 systems such as manufacturing, healthcare, government, and critical infrastructure. Successful exploitation could lead to unauthorized code execution, enabling attackers to steal sensitive data, disrupt operations, or deploy ransomware and other malware. The requirement for local access and user interaction limits remote mass exploitation but does not eliminate risk in environments where insider threats or phishing attacks can deliver malicious payloads. Organizations with insufficient endpoint security or lax PowerShell usage policies are particularly vulnerable. The compromise of systems in critical sectors could have cascading effects on service availability and data integrity, impacting national security and economic stability. Additionally, compliance with European data protection regulations (e.g., GDPR) could be jeopardized if data breaches occur due to exploitation of this vulnerability.

1. Apply security patches promptly once Microsoft releases an official update addressing CVE-2025-54100. 2. Restrict PowerShell usage to only trusted administrators and users, employing application control policies such as AppLocker or Windows Defender Application Control. 3. Enforce strict input validation and sanitization in scripts and applications invoking PowerShell commands to prevent injection of malicious elements. 4. Implement endpoint detection and response (EDR) solutions to monitor and alert on suspicious PowerShell activity, including unusual command execution patterns. 5. Educate users about the risks of executing untrusted scripts or commands and enforce policies to minimize user interaction with potentially harmful content. 6. Consider upgrading legacy systems from Windows 10 Version 1809 to supported, patched versions of Windows to reduce exposure. 7. Use PowerShell constrained language mode or Just Enough Administration (JEA) to limit the scope of commands users can execute. 8. Regularly audit and review PowerShell logs to detect anomalous behavior indicative of exploitation attempts.