CVE-2021-44226
📋 TL;DR
This vulnerability allows local privilege escalation in Razer Synapse software. An unprivileged user can create a directory and place malicious DLLs before installation, which are then executed with elevated privileges when the service runs. This affects Windows systems running vulnerable versions of Razer Synapse.
💻 Affected Systems
- Razer Synapse
📦 What is this software?
Synapse by Razer
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where an attacker gains SYSTEM/administrator privileges, installs persistent malware, accesses sensitive data, and disables security controls.
Likely Case
Local attacker escalates privileges from standard user to administrator to install additional malware, modify system settings, or access protected resources.
If Mitigated
Limited impact with proper user privilege separation, application whitelisting, and directory permissions preventing unauthorized DLL placement.
🎯 Exploit Status
Multiple public exploit details available in Packet Storm and Full Disclosure archives. Requires local access and ability to create directories/files.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.7.0228.022817 and later
Vendor Advisory: Not publicly documented in vendor advisory
Restart Required: Yes
Instructions:
1. Open Razer Synapse application
2. Check for updates in settings
3. Install version 3.7.0228.022817 or newer
4. Restart the system
🔧 Temporary Workarounds
Secure directory permissions
windowsSet restrictive permissions on %PROGRAMDATA%\Razer to prevent unprivileged users from creating/modifying files
icacls "%PROGRAMDATA%\Razer" /inheritance:r /grant:r "SYSTEM:(OI)(CI)F" /grant:r "Administrators:(OI)(CI)F" /deny "Users:(OI)(CI)(W)"
Remove vulnerable software
windowsUninstall Razer Synapse if not required for essential functionality
appwiz.cpl
Select Razer Synapse and click Uninstall
🧯 If You Can't Patch
- Monitor %PROGRAMDATA%\Razer\Synapse3\Service\bin directory for unauthorized DLL creation
- Implement application control/whitelisting to prevent execution of unauthorized binaries
🔍 How to Verify
Check if Vulnerable:
Check Razer Synapse version in application settings or via 'wmic product where name="Razer Synapse" get version'Check Version:
wmic product where name="Razer Synapse" get versionVerify Fix Applied:
Confirm version is 3.7.0228.022817 or newer and verify %PROGRAMDATA%\Razer directory permissions are secure📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing DLL loading from %PROGRAMDATA%\Razer\Synapse3\Service\bin
- Process creation events for RazerSynapseService.exe with suspicious parent processes
Network Indicators:
- Unusual outbound connections from Razer Synapse processes
SIEM Query:
EventID=4688 AND (NewProcessName:*RazerSynapseService.exe* OR NewProcessName:*Razer Central.exe*) | stats count by ParentProcessName, NewProcessName🔗 References
- http://packetstormsecurity.com/files/166485/Razer-Synapse-3.6.x-DLL-Hijacking.html
- http://packetstormsecurity.com/files/170772/Razer-Synapse-3.7.0731.072516-Local-Privilege-Escalation.html
- http://packetstormsecurity.com/files/174696/Razer-Synapse-Race-Condition-DLL-Hijacking.html
- http://seclists.org/fulldisclosure/2022/Mar/51
- http://seclists.org/fulldisclosure/2023/Jan/26
- http://seclists.org/fulldisclosure/2023/Sep/6
- https://www.razer.com/community
- https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2021-058.txt
- http://packetstormsecurity.com/files/166485/Razer-Synapse-3.6.x-DLL-Hijacking.html
- http://packetstormsecurity.com/files/170772/Razer-Synapse-3.7.0731.072516-Local-Privilege-Escalation.html
- http://packetstormsecurity.com/files/174696/Razer-Synapse-Race-Condition-DLL-Hijacking.html
- http://seclists.org/fulldisclosure/2022/Mar/51
- http://seclists.org/fulldisclosure/2023/Jan/26
- http://seclists.org/fulldisclosure/2023/Sep/6
- https://www.razer.com/community
- https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2021-058.txt
