CVE-2025-54100: Windows 10 1607 PowerShell RCE Flaw

CVE-2025-54100 Overview

CVE-2025-54100 is a command injection vulnerability in Windows PowerShell that allows an unauthorized attacker to execute arbitrary code locally. The vulnerability stems from improper neutralization of special elements used in commands (CWE-77), enabling attackers to inject malicious commands that are then executed within the PowerShell environment.

This vulnerability affects a broad range of Windows operating systems, including multiple versions of Windows 10, Windows 11, and Windows Server editions dating back to Windows Server 2008. The local attack vector requires user interaction, but successful exploitation grants the attacker full control over confidentiality, integrity, and availability of the affected system.

Critical Impact

Successful exploitation enables unauthorized local code execution on affected Windows systems, potentially leading to complete system compromise, data theft, and lateral movement within enterprise networks.

Affected Products

• Microsoft Windows 10 (versions 1607, 1809, 21H2, 22H2)
• Microsoft Windows 11 (versions 23H2, 24H2, 25H2)
• Microsoft Windows Server 2008 SP2 and R2 SP1
• Microsoft Windows Server 2012 and R2
• Microsoft Windows Server 2016, 2019, 2022, 2022 23H2, and 2025

Discovery Timeline

• December 9, 2025 - CVE-2025-54100 published to NVD
• December 24, 2025 - Last updated in NVD database

Technical Details for CVE-2025-54100

Vulnerability Analysis

This command injection vulnerability exists in Windows PowerShell due to improper neutralization of special elements within command strings. When PowerShell processes certain inputs, it fails to adequately sanitize special characters and command sequences, allowing an attacker to inject arbitrary commands that execute within the context of the PowerShell session.

The vulnerability requires local access and user interaction to exploit. An attacker must craft malicious input that, when processed by PowerShell, escapes the intended command context and executes attacker-controlled code. This could occur through various attack vectors such as malicious scripts, specially crafted command-line arguments, or poisoned configuration files that are processed by PowerShell.

Successful exploitation results in code execution with the privileges of the user running PowerShell, potentially allowing attackers to install programs, view and modify data, or create new accounts with full user rights.

Root Cause

The root cause is improper input validation and sanitization in PowerShell's command parsing logic. Special characters and metacharacters that have meaning within the PowerShell command interpreter are not properly escaped or neutralized before being processed. This allows specially crafted input to break out of the expected command context and inject additional commands.

The vulnerability is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command), which describes flaws where software constructs commands using externally-influenced input without properly neutralizing elements that could modify the intended command.

Attack Vector

The attack vector is local, requiring the attacker to have access to the target system and the ability to interact with PowerShell. The attack requires user interaction, typically involving social engineering to convince a user to execute a malicious script or open a specially crafted file that triggers the vulnerability.

Attack scenarios may include:

• Delivery of malicious PowerShell scripts via phishing
• Exploitation through compromised software installers that invoke PowerShell
• Malicious documents or files that trigger PowerShell execution with crafted parameters
• Abuse of legitimate applications that pass unsanitized user input to PowerShell

The vulnerability mechanism involves injecting metacharacters into command strings processed by PowerShell. When these characters are not properly sanitized, the injected content is interpreted as additional commands. Detailed technical analysis is available in the Microsoft Security Response Center advisory.

Detection Methods for CVE-2025-54100

Indicators of Compromise

• Unusual PowerShell process spawning with encoded or obfuscated command-line arguments
• PowerShell execution with unexpected parent processes or execution chains
• Suspicious PowerShell script block logging entries showing command injection patterns
• Unexpected child processes spawned by powershell.exe or pwsh.exe
• Evidence of command concatenation characters (;, |, &) in PowerShell arguments where not expected

Detection Strategies

• Enable PowerShell Script Block Logging (Event ID 4104) to capture all script content executed
• Monitor Windows Event Log for Event ID 4688 (Process Creation) with PowerShell as the process
• Implement behavioral detection for PowerShell processes spawning unexpected child processes
• Deploy endpoint detection rules for command injection patterns in PowerShell arguments
• Utilize AMSI (Antimalware Scan Interface) integration to inspect PowerShell content in real-time

Monitoring Recommendations

• Configure centralized logging for PowerShell events across all Windows endpoints
• Establish baselines for normal PowerShell usage patterns in your environment
• Alert on PowerShell executions from non-standard directories or with unusual parameters
• Monitor for PowerShell constrained language mode bypass attempts
• Implement real-time correlation of PowerShell execution events with network activity

How to Mitigate CVE-2025-54100

Immediate Actions Required

• Apply the latest Windows security updates from Microsoft immediately
• Enable PowerShell Constrained Language Mode where feasible to limit execution capabilities
• Review and restrict PowerShell execution policies using Set-ExecutionPolicy
• Audit systems to identify unpatched Windows installations
• Implement application allowlisting to control PowerShell script execution

Patch Information

Microsoft has released security updates to address this vulnerability. Patches are available through Windows Update, Windows Server Update Services (WSUS), and the Microsoft Update Catalog. Organizations should consult the Microsoft Security Update Guide for specific patch details and download links for each affected product version.

Priority should be given to patching systems that handle sensitive data or have elevated network access. Servers and workstations in critical infrastructure should be patched during the next available maintenance window.

Workarounds

• Enable PowerShell Constrained Language Mode to restrict dangerous language elements
• Configure AppLocker or Windows Defender Application Control policies to control script execution
• Disable PowerShell 2.0 (legacy version) which lacks modern security features
• Implement Just Enough Administration (JEA) to limit PowerShell capabilities for administrative tasks
• Use PowerShell remoting with proper authentication instead of local execution where possible

# Enable PowerShell Constrained Language Mode via Group Policy
# Computer Configuration > Administrative Templates > Windows Components > Windows PowerShell
# Set "Turn on PowerShell Script Block Logging" to Enabled
# Set "Turn on PowerShell Transcription" to Enabled

# Alternatively, set execution policy via PowerShell (requires administrator):
Set-ExecutionPolicy -ExecutionPolicy AllSigned -Scope LocalMachine -Force

# Disable PowerShell 2.0 (Windows Feature):
Disable-WindowsOptionalFeature -Online -FeatureName MicrosoftWindowsPowerShellV2Root