CVE-2025-41421
📋 TL;DR
This vulnerability allows attackers with local, unprivileged access to escalate privileges by exploiting improper symbolic link handling in TeamViewer's update mechanism. It affects Windows systems running TeamViewer Full Client and Host versions before 15.70. Attackers can spoof update file paths to gain unauthorized access to sensitive information.
💻 Affected Systems
- TeamViewer Full Client for Windows
- TeamViewer Host for Windows
⚠️ 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
Complete system compromise with administrative privileges, enabling data theft, malware installation, and persistence mechanisms.
Likely Case
Local privilege escalation allowing unauthorized access to sensitive files and system resources on the compromised machine.
If Mitigated
Limited impact due to proper malware protection and restricted local access controls.
🎯 Exploit Status
Requires local access and knowledge of symbolic link manipulation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 15.70 or later
Vendor Advisory: https://www.teamviewer.com/en/resources/trust-center/security-bulletins/tv-2025-1004/
Restart Required: Yes
Instructions:
1. Open TeamViewer application. 2. Go to Help > Check for new version. 3. Follow the update prompts to install version 15.70 or later. 4. Restart the system after installation.
🔧 Temporary Workarounds
Restrict local user access
windowsLimit local user accounts and implement least privilege principles to reduce attack surface.
Enable Windows Defender or third-party antivirus
windowsEnsure real-time malware protection is active to detect and block exploitation attempts.
🧯 If You Can't Patch
- Implement strict access controls to prevent unauthorized local access to systems.
- Monitor for suspicious file system activities involving symbolic links and TeamViewer directories.
🔍 How to Verify
Check if Vulnerable:
Check TeamViewer version in the application's About dialog or via 'TeamViewer.exe --version' command.Check Version:
TeamViewer.exe --versionVerify Fix Applied:
Confirm version is 15.70 or higher in the About dialog or via version check command.📡 Detection & Monitoring
Log Indicators:
- Unusual file system access to TeamViewer update directories
- Creation of symbolic links in TeamViewer installation paths
Network Indicators:
- None - this is a local privilege escalation vulnerability
SIEM Query:
EventID=4663 AND ObjectName LIKE '%TeamViewer%' AND AccessMask IN ('0x10000', '0x2')