CVE-2023-43687
📋 TL;DR
A race condition vulnerability in Malwarebytes and Nebula products allows attackers to execute arbitrary code by exploiting timing gaps between file verification and execution. This affects users running vulnerable versions of Malwarebytes antivirus software and Nebula cloud management platform.
💻 Affected Systems
- Malwarebytes
- Malwarebytes Nebula
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining SYSTEM/root privileges and persistent access to the infected machine.
Likely Case
Local privilege escalation allowing attackers to bypass security controls and install malware or steal sensitive data.
If Mitigated
Limited impact due to proper patch management and endpoint security controls preventing exploitation attempts.
🎯 Exploit Status
Exploitation requires local access and precise timing to win the race condition between verification and execution phases.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Malwarebytes 4.6.14.326 or 5.1.5.116 and later; Nebula updates as per vendor advisory
Vendor Advisory: https://www.malwarebytes.com/secure/cves/cve-2023-43687
Restart Required: No
Instructions:
1. Open Malwarebytes application. 2. Click Settings > About. 3. Check version number. 4. If vulnerable, enable automatic updates or manually update through the application interface. 5. For Nebula, follow cloud console update instructions.
🔧 Temporary Workarounds
Disable automatic file scanning
allTemporarily disable real-time file scanning to reduce attack surface while awaiting patch
🧯 If You Can't Patch
- Implement application whitelisting to prevent unauthorized executables from running
- Use endpoint detection and response (EDR) tools to monitor for suspicious file execution patterns
🔍 How to Verify
Check if Vulnerable:
Check Malwarebytes version in Settings > About. If version is below 4.6.14.326 for version 4.x or below 5.1.5.116 for version 5.x, system is vulnerable.Check Version:
On Windows: Check Malwarebytes GUI Settings > About. On macOS: Open Malwarebytes > About Malwarebytes.Verify Fix Applied:
Confirm version is 4.6.14.326 or higher for version 4.x, or 5.1.5.116 or higher for version 5.x in Settings > About.📡 Detection & Monitoring
Log Indicators:
- Unusual file execution patterns from Malwarebytes processes
- Multiple rapid file verification attempts
Network Indicators:
- None - this is a local privilege escalation vulnerability
SIEM Query:
Process creation events where parent process is MalwarebytesService.exe with unusual file paths or timing patterns