CVE-2021-33592
📋 TL;DR
CVE-2021-33592 is a critical remote code execution vulnerability in NAVER Toolbar that allows attackers to bypass code signing checks and execute arbitrary code by providing a specially crafted upgrade.xml file. This affects all users of NAVER Toolbar before version 4.0.30.323. Attackers can exploit this remotely without authentication.
💻 Affected Systems
- NAVER Toolbar
📦 What is this software?
Toolbar by Naver
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the affected system, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Remote code execution leading to malware installation, credential theft, or system disruption for affected users.
If Mitigated
No impact if the vulnerable version is not installed or has been patched to version 4.0.30.323 or later.
🎯 Exploit Status
The vulnerability allows bypassing code signing checks, making exploitation straightforward once the technique is understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.0.30.323 and later
Vendor Advisory: https://cve.naver.com/detail/cve-2021-33592
Restart Required: Yes
Instructions:
1. Open NAVER Toolbar. 2. Check for updates in settings. 3. Update to version 4.0.30.323 or later. 4. Restart the application.
🔧 Temporary Workarounds
Disable automatic updates
windowsPrevent the toolbar from automatically downloading and processing upgrade.xml files
Navigate to NAVER Toolbar settings and disable automatic updates
Uninstall NAVER Toolbar
windowsRemove the vulnerable software entirely
Control Panel > Programs > Uninstall a program > Select NAVER Toolbar > Uninstall
🧯 If You Can't Patch
- Implement network filtering to block malicious upgrade.xml files
- Use application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check NAVER Toolbar version in application settings or Control Panel > ProgramsCheck Version:
Not applicable - check through GUI settingsVerify Fix Applied:
Verify version is 4.0.30.323 or higher in application settings📡 Detection & Monitoring
Log Indicators:
- Unusual upgrade.xml file downloads
- Process execution from NAVER Toolbar directory
Network Indicators:
- HTTP requests to download upgrade.xml from unusual sources
SIEM Query:
Process creation where parent process is NAVER Toolbar and command line contains suspicious parameters