CVE-2021-30605
📋 TL;DR
This vulnerability allows attackers to bypass discretionary access controls on Windows systems running vulnerable versions of the ChromeOS Readiness Tool installer. By loosening DCOM access rights, attackers could potentially execute unauthorized actions or escalate privileges. Only Windows users who installed ChromeOS Readiness Tool versions before 1.0.2.0 are affected.
💻 Affected Systems
- ChromeOS Readiness Tool
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An attacker could gain unauthorized access to DCOM objects, potentially leading to privilege escalation, remote code execution, or complete system compromise.
Likely Case
Local attackers could bypass access controls to manipulate DCOM objects, potentially gaining elevated privileges or accessing restricted system resources.
If Mitigated
With proper access controls and updated software, the risk is limited to unauthorized DCOM object access attempts that would be blocked.
🎯 Exploit Status
Exploitation requires local access to the Windows system and knowledge of DCOM object manipulation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.2.0
Vendor Advisory: https://crbug.com/1240952
Restart Required: Yes
Instructions:
1. Download ChromeOS Readiness Tool version 1.0.2.0 or later from official Google sources. 2. Uninstall any previous versions. 3. Install the updated version. 4. Restart the Windows system.
🔧 Temporary Workarounds
Uninstall ChromeOS Readiness Tool
windowsRemove the vulnerable software entirely if not needed
Control Panel > Programs > Uninstall a program > Select 'ChromeOS Readiness Tool' > Uninstall
Restrict DCOM Access
windowsManually tighten DCOM access controls using Windows security settings
dcomcnfg.exe > Component Services > Computers > My Computer > DCOM Config > Configure specific application permissions
🧯 If You Can't Patch
- Uninstall ChromeOS Readiness Tool if not required for operations
- Implement strict access controls and monitor for unusual DCOM object access attempts
🔍 How to Verify
Check if Vulnerable:
Check installed programs for ChromeOS Readiness Tool version earlier than 1.0.2.0 via Control Panel or PowerShell: Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -like '*ChromeOS Readiness Tool*'} | Select-Object Name, VersionCheck Version:
Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -like '*ChromeOS Readiness Tool*'} | Select-Object VersionVerify Fix Applied:
Confirm ChromeOS Readiness Tool version is 1.0.2.0 or later using same PowerShell command or program properties📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing unusual DCOM activation attempts
- Security logs with access control violations for DCOM objects
Network Indicators:
- Local DCOM/RPC communication patterns that deviate from normal
SIEM Query:
EventID=4688 OR EventID=4662 AND ProcessName LIKE '%dcom%' AND TargetObject LIKE '%ChromeOS%'