CVE-2025-20708
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected devices by exploiting an out-of-bounds write in the modem firmware when connected to a malicious base station. It affects devices with MediaTek modems that haven't applied the security patch. No user interaction is required for exploitation.
💻 Affected Systems
- Devices with MediaTek modems
📦 What is this software?
Nr15 by Mediatek
Nr16 by Mediatek
Nr17 by Mediatek
Nr17r by Mediatek
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attacker to install persistent malware, access sensitive data, and use device as pivot point in network.
Likely Case
Remote code execution leading to data theft, surveillance capabilities, or device bricking.
If Mitigated
Limited impact with proper network segmentation and base station authentication controls.
🎯 Exploit Status
Requires attacker to operate rogue base station. No authentication needed for exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patch ID: MOLY01123853
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/September-2025
Restart Required: Yes
Instructions:
1. Contact device manufacturer for firmware update 2. Apply modem firmware patch MOLY01123853 3. Reboot device 4. Verify patch installation
🔧 Temporary Workarounds
Disable automatic network switching
allPrevent device from automatically connecting to unknown base stations
Device-specific: Check network settings for 'automatic network selection'
Use manual network selection
allOnly connect to trusted, known cellular networks
Device-specific: Set network mode to manual selection
🧯 If You Can't Patch
- Isolate affected devices on separate network segments
- Implement cellular network monitoring for rogue base station detection
🔍 How to Verify
Check if Vulnerable:
Check modem firmware version against vendor patch notes. Contact device manufacturer for specific version information.Check Version:
Device-specific: Typically in Settings > About Phone > Baseband VersionVerify Fix Applied:
Verify modem firmware has been updated to version containing patch MOLY01123853📡 Detection & Monitoring
Log Indicators:
- Unexpected base station connections
- Modem firmware crash logs
- Unusual cellular network handoffs
Network Indicators:
- Connections to unknown cell tower IDs
- Unusual signal strength patterns
- Suspicious base station broadcasts
SIEM Query:
source="modem_logs" AND (event="connection_failure" OR event="unexpected_handoff")