CVE-2021-32484
📋 TL;DR
This vulnerability allows remote attackers to cause a denial of service via a heap buffer overflow in the 2G Radio Resource Management (RRM) modem component. It affects devices using MediaTek modems with the vulnerable firmware. No user interaction or special privileges are required for exploitation.
💻 Affected Systems
- MediaTek modem chipsets
📦 What is this software?
Modem by Mediatek
Modem by Mediatek
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash requiring device reboot, potentially disrupting cellular connectivity and device functionality.
Likely Case
Temporary denial of service affecting cellular connectivity until device reboots.
If Mitigated
No impact if patched; limited impact if network controls block malicious 2G traffic.
🎯 Exploit Status
Requires sending specially crafted 2G network packets to vulnerable device.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware with patch ID MOLY00500621
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/September-2021
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply MediaTek modem firmware update containing patch MOLY00500621. 3. Reboot device after update.
🔧 Temporary Workarounds
Disable 2G connectivity
androidConfigure device to use only 3G/4G/5G networks to avoid 2G attack vector
Settings > Network & Internet > Mobile network > Preferred network type > Select 3G/4G/5G only
🧯 If You Can't Patch
- Implement network-level filtering to block suspicious 2G traffic
- Use device management policies to restrict cellular network access in high-risk environments
🔍 How to Verify
Check if Vulnerable:
Check modem firmware version against MediaTek security bulletin for affected versionsCheck Version:
adb shell getprop | grep gsm.version.baseband (for Android devices)Verify Fix Applied:
Verify modem firmware has been updated to version containing patch MOLY00500621📡 Detection & Monitoring
Log Indicators:
- Modem crash logs
- Unexpected device reboots
- Cellular connectivity loss events
Network Indicators:
- Unusual 2G network traffic patterns
- Malformed 2G protocol packets
SIEM Query:
EventID: DeviceCrash AND Source: Modem OR EventID: NetworkDisconnect AND Interface: Cellular