CVE-2023-43683
📋 TL;DR
A stack buffer out-of-bounds access vulnerability exists in Malwarebytes and Nebula products due to integer underflow when handling newline characters. This could allow attackers to potentially execute arbitrary code or cause denial of service. Affects Malwarebytes 4.6.14.326 and earlier versions before 5.1.5.116, and Nebula 2020-10-21 and later.
💻 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
Remote code execution leading to complete system compromise, privilege escalation, or malware persistence
Likely Case
Application crash causing denial of service, potentially disrupting security monitoring
If Mitigated
Limited impact due to security software sandboxing and exploit mitigations
🎯 Exploit Status
Exploitation requires triggering the vulnerable code path through specific input. No public exploits known as of knowledge cutoff.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Malwarebytes 5.1.5.116 or later
Vendor Advisory: https://www.malwarebytes.com/secure/cves/cve-2023-43683
Restart Required: No
Instructions:
1. Open Malwarebytes application. 2. Click Settings. 3. Click About tab. 4. Click Check for Updates. 5. Install available updates. 6. For Nebula: Update through Nebula console to latest version.
🔧 Temporary Workarounds
Disable real-time protection temporarily
WindowsTemporarily disable real-time scanning to reduce attack surface while planning update
Right-click Malwarebytes tray icon → Disable Real-Time Protection
🧯 If You Can't Patch
- Implement network segmentation to limit exposure of systems running vulnerable versions
- Deploy additional endpoint detection and response (EDR) solutions to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check Malwarebytes version: Open application → Settings → About tab → verify version is below 5.1.5.116Check Version:
wmic product where name="Malwarebytes" get versionVerify Fix Applied:
Confirm version is 5.1.5.116 or higher in About tab, ensure no crash events in Windows Event Logs📡 Detection & Monitoring
Log Indicators:
- Application crash logs from Malwarebytes service
- Windows Event ID 1000 or 1001 for mbam.exe crashes
- Unexpected process termination of Malwarebytes components
Network Indicators:
- Unusual outbound connections from Malwarebytes processes
- Traffic to unexpected update servers
SIEM Query:
EventID=1000 OR EventID=1001 AND ProcessName="mbam.exe" OR Source="Malwarebytes Service"