CVE-2025-54100
📋 TL;DR
This command injection vulnerability in Windows PowerShell allows attackers to execute arbitrary code on affected systems. It affects Windows systems running vulnerable PowerShell versions, primarily impacting organizations using PowerShell for administration or automation.
💻 Affected Systems
- Windows PowerShell
📦 What is this software?
Windows 10 1607 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
Windows 11 25h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining SYSTEM privileges, lateral movement across network, data exfiltration, and ransomware deployment.
Likely Case
Local privilege escalation leading to credential theft, persistence establishment, and limited lateral movement within the environment.
If Mitigated
Contained impact with limited privilege escalation if proper application whitelisting and PowerShell constraints are enforced.
🎯 Exploit Status
Requires local access or ability to execute PowerShell commands; may be chained with other vulnerabilities for remote exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific patch versions
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-54100
Restart Required: Yes
Instructions:
1. Apply latest Windows security updates via Windows Update
2. For enterprise: Deploy through WSUS or Microsoft Endpoint Configuration Manager
3. Verify PowerShell version after update
🔧 Temporary Workarounds
Enable PowerShell Constrained Language Mode
windowsRestricts PowerShell to safe language elements preventing command injection
Set-ExecutionPolicy -ExecutionPolicy Restricted
Enable PowerShell logging via Group Policy
Implement Application Control
windowsUse Windows Defender Application Control to restrict PowerShell execution
Configure AppLocker or WDAC policies to control PowerShell usage
🧯 If You Can't Patch
- Implement strict PowerShell logging and monitoring for suspicious command patterns
- Apply network segmentation to limit lateral movement from compromised systems
🔍 How to Verify
Check if Vulnerable:
Check PowerShell version and compare with patched versions in Microsoft advisoryCheck Version:
$PSVersionTable.PSVersionVerify Fix Applied:
Verify Windows Update history shows the security patch applied and PowerShell version updated📡 Detection & Monitoring
Log Indicators:
- PowerShell logs showing unusual command execution patterns
- Event ID 4104 with suspicious script blocks in Windows Event Logs
- Unexpected PowerShell processes with unusual arguments
Network Indicators:
- Unusual outbound connections from systems running PowerShell
- Lateral movement attempts following PowerShell execution
SIEM Query:
source="Windows PowerShell" AND (command="*Invoke-Expression*" OR command="*iex*" OR command="*&*" OR command="*|*" WITH suspicious parameters)