CVE-2025-20637
📋 TL;DR
This vulnerability in MediaTek network hardware allows remote attackers to cause a system hang (denial of service) without authentication or user interaction. It affects devices using vulnerable MediaTek chipsets. The issue stems from an uncaught exception that can be triggered remotely.
💻 Affected Systems
- MediaTek network hardware chipsets
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Permanent system hang requiring physical power cycle or hardware replacement, disrupting all network services on affected devices.
Likely Case
Temporary system hang requiring reboot, causing service disruption until system restarts.
If Mitigated
Minimal impact if patched; unpatched systems remain vulnerable to remote DoS attacks.
🎯 Exploit Status
No authentication required, but specific network conditions or packet crafting may be needed to trigger the uncaught exception.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply patch ID: WCNCR00399035
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/February-2025
Restart Required: Yes
Instructions:
1. Identify affected MediaTek hardware devices. 2. Contact MediaTek or device manufacturer for patch WCNCR00399035. 3. Apply firmware update containing the patch. 4. Reboot device to activate patch.
🔧 Temporary Workarounds
Network segmentation and access control
allRestrict network access to vulnerable devices using firewalls or ACLs to limit potential attackers.
Traffic filtering
allImplement network monitoring to detect and block malicious traffic patterns that might trigger the vulnerability.
🧯 If You Can't Patch
- Isolate vulnerable devices in separate network segments with strict access controls
- Implement redundant systems to maintain availability if devices become unavailable
🔍 How to Verify
Check if Vulnerable:
Check device firmware version and compare against vendor's patched versions list; devices using MediaTek network hardware with unpatched firmware are vulnerable.Check Version:
Device-specific; typically 'show version' or similar in device CLI, or check firmware version in management interface.Verify Fix Applied:
Verify patch WCNCR00399035 is applied by checking firmware version or patch status in device management interface.📡 Detection & Monitoring
Log Indicators:
- System hang/crash logs
- Unexpected reboots
- Network interface errors
Network Indicators:
- Unusual traffic patterns to network hardware
- Service disruption alerts
SIEM Query:
source="network_device" AND (event_type="crash" OR event_type="hang" OR event_type="reboot")