CVE-2021-31518
📋 TL;DR
Trend Micro Home Network Security 6.5.599 and earlier contains a file-parsing vulnerability that could allow an attacker to cause a denial-of-service condition on the device. This affects all users running vulnerable versions of the software. The vulnerability is similar to CVE-2021-31517 but not identical.
💻 Affected Systems
- Trend Micro Home Network Security
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device unavailability requiring physical reset or reinstallation
Likely Case
Temporary service disruption until device automatically restarts
If Mitigated
No impact if patched to version 6.5.600 or later
🎯 Exploit Status
Exploitation requires sending specially crafted files to the device's management interface
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.5.600
Vendor Advisory: https://helpcenter.trendmicro.com/en-us/article/TMKA-10312
Restart Required: Yes
Instructions:
1. Open Trend Micro Home Network Security console
2. Navigate to Settings > Update
3. Click 'Check for Updates'
4. Install version 6.5.600 or later
5. Restart the device when prompted
🔧 Temporary Workarounds
Restrict Management Interface Access
allLimit access to the device management interface to trusted networks only
🧯 If You Can't Patch
- Isolate the device on a separate VLAN with restricted access
- Implement network monitoring for unusual file upload attempts to the management interface
🔍 How to Verify
Check if Vulnerable:
Check the software version in the Trend Micro Home Network Security console under Settings > AboutCheck Version:
Not applicable - check through GUI interface onlyVerify Fix Applied:
Verify version is 6.5.600 or later in Settings > About📡 Detection & Monitoring
Log Indicators:
- Multiple failed file parsing attempts in device logs
- Unexpected device restarts
Network Indicators:
- Unusual file uploads to device management port (typically 443)
SIEM Query:
Not applicable for consumer-grade security appliances