CVE-2019-16897
📋 TL;DR
This vulnerability in K7 Security products allows local attackers to escalate privileges by exploiting improper privilege validation in K7TSHlpr.dll. Attackers can write arbitrary registry values through K7AVOptn.dll to gain administrative access. Users of K7 Antivirus Premium, K7 Total Security, and K7 Ultimate Security versions 16.0.xxx through 16.0.0120 are affected.
💻 Affected Systems
- K7 Antivirus Premium
- K7 Total Security
- K7 Ultimate Security
📦 What is this software?
K7 Total Security by K7computing
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains full SYSTEM/administrator privileges on the compromised machine, enabling complete system takeover, data theft, and persistence establishment.
Likely Case
Local user with limited privileges escalates to administrator to install malware, disable security controls, or access protected resources.
If Mitigated
Attack fails due to proper privilege separation, user account controls, or security monitoring detecting suspicious registry writes.
🎯 Exploit Status
Exploit requires local user access but minimal technical skill. Public proof-of-concept demonstrates the privilege escalation technique.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 16.0.0120
Vendor Advisory: Not publicly documented in vendor advisory
Restart Required: Yes
Instructions:
1. Open K7 Security product. 2. Check for updates in settings. 3. Install available updates. 4. Restart computer to ensure patch is fully applied.
🔧 Temporary Workarounds
Remove vulnerable K7 components
windowsUninstall affected K7 Security products and replace with alternative antivirus solution
Control Panel > Programs > Uninstall a program > Select K7 product > Uninstall
Restrict registry access
windowsApply registry permissions to limit write access to K7-related registry keys
regedit > Navigate to HKLM\SOFTWARE\K7 Computing > Right-click > Permissions > Restrict write access
🧯 If You Can't Patch
- Implement strict user privilege separation - ensure users operate with minimal necessary privileges
- Monitor registry modifications to K7-related keys using Windows Event Log or security monitoring tools
🔍 How to Verify
Check if Vulnerable:
Check K7 product version in About section. If version is 16.0.0120 or earlier, system is vulnerable.Check Version:
wmic product where "name like '%K7%'" get versionVerify Fix Applied:
Verify K7 product version is higher than 16.0.0120 and test privilege escalation attempts fail.📡 Detection & Monitoring
Log Indicators:
- Unusual registry writes to HKLM\SOFTWARE\K7 Computing paths
- Process creation from low-privilege user to K7 service processes
Network Indicators:
- Local inter-process communication spikes between K7 components
SIEM Query:
EventID=4657 OR EventID=4663 AND ObjectName LIKE '%K7%' AND AccessMask='0x2' (Write access)