CVE-2021-46247
📋 TL;DR
CVE-2021-46247 is a hard-coded cryptographic key vulnerability in ASUS CMAX6000 routers that allows attackers to decrypt encrypted data. This affects all users of ASUS CMAX6000 v1.02.00 who rely on the device's encryption for data protection.
💻 Affected Systems
- ASUS CMAX6000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers decrypt all encrypted communications and stored data, potentially exposing sensitive information, credentials, and network traffic.
Likely Case
Local network attackers or those with physical access decrypt intercepted encrypted data from the router.
If Mitigated
With network segmentation and monitoring, impact is limited to isolated network segments.
🎯 Exploit Status
Exploitation requires access to encrypted data but no authentication to the device itself. The hard-coded key makes decryption trivial once encrypted data is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.02.01 or later
Vendor Advisory: https://www.asus.com/support/FAQ/1048284/
Restart Required: Yes
Instructions:
1. Log into ASUS router admin interface. 2. Navigate to Firmware Upgrade section. 3. Download latest firmware from ASUS support site. 4. Upload and install firmware update. 5. Reboot router after installation completes.
🔧 Temporary Workarounds
Disable router encryption features
allTurn off any encryption services on the router that use the vulnerable cryptographic implementation
Use external VPN/encryption
allRoute all sensitive traffic through external VPN or encryption services not dependent on router encryption
🧯 If You Can't Patch
- Segment network to isolate ASUS CMAX6000 from sensitive systems
- Monitor network traffic for unusual decryption attempts or data exfiltration
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System Log > General Log or Firmware Version pageCheck Version:
Login to router web interface and check Firmware Version in System SettingsVerify Fix Applied:
Verify firmware version is v1.02.01 or higher after update📡 Detection & Monitoring
Log Indicators:
- Multiple failed decryption attempts
- Unusual access to encrypted data stores
Network Indicators:
- Unexpected decryption of router management traffic
- Traffic patterns suggesting encrypted data interception
SIEM Query:
source="router_logs" AND ("decryption" OR "crypto" OR "key") AND severity>=medium