Critical Windows PowerShell Vulnerability Exposes Systems to Malicious Code Execution
A significant security flaw has been identified in Windows PowerShell, designated as CVE-2025-54100, which allows unauthorized attackers to execute arbitrary code on affected systems. This vulnerability, publicly disclosed on December 9, 2025, poses a substantial risk to organizations and individual users worldwide.
Understanding the Vulnerability
The core issue arises from improper neutralization of special elements within Windows PowerShell during command injection attacks. This flaw enables attackers to craft specific commands that, when executed, can run malicious code on the targeted system. The vulnerability is categorized under CWE-77, which pertains to improper neutralization of special elements used in command injection.
Technical Details
– CVE Identifier: CVE-2025-54100
– Attack Vector: Local
– CVSS Score: 7.8 (High)
– Impact Type: Remote Code Execution
– Affected Component: Windows PowerShell
The vulnerability affects a broad spectrum of Windows operating systems, including:
– Windows 10
– Windows 11
– Windows Server versions from 2008 through 2025
This widespread impact underscores the critical nature of the flaw and the necessity for prompt remediation.
Exploitation and Risk Assessment
While Microsoft currently assesses the likelihood of real-world exploitation as low, the public disclosure of the vulnerability increases the risk of potential attacks. Exploitation requires local access and user interaction, meaning attackers would typically need to deceive users into executing malicious files or commands. Despite these prerequisites, the severity of the vulnerability warrants immediate attention.
Mitigation and Remediation
Microsoft has released security updates to address this vulnerability across various platforms. The specific patch versions depend on the operating system and its configuration:
– Windows Server 2025, Windows 11 versions 24H2 and 25H2, Windows Server 2022: Apply KB5072033 or KB5074204.
– Windows 10 and earlier versions: Apply KB5071546 or KB5071544.
It’s important to note that installing these updates may require a system reboot to fully implement the fixes.
Additional Security Measures
Post-update, users employing security updates KB5074204 or KB5074353 will encounter a security warning when using the `Invoke-WebRequest` command in PowerShell. To mitigate this, Microsoft recommends utilizing the `UseBasicParsing` switch, which prevents script code execution from web content.
Furthermore, organizations should implement the guidance provided in KB5074596 concerning PowerShell 5.1 security measures. These measures are designed to mitigate risks associated with script execution and enhance overall system security.
Conclusion
The discovery of CVE-2025-54100 highlights the ongoing challenges in securing widely used system components like Windows PowerShell. Given the potential for malicious code execution, it is imperative for organizations and individual users to apply the recommended security updates promptly. Staying vigilant and adhering to best practices in system security are essential steps in protecting against emerging threats.
