How CVE-2025-20670 Works
CVE-2025-20670 is a critical vulnerability in MediaTek modems due to improper certificate validation during base station handshakes. When a User Equipment (UE) connects to a rogue base station, the modem fails to verify the authenticity of the station’s TLS/SSL certificate. This allows attackers to impersonate legitimate cell towers, intercept traffic, or disclose sensitive user data. Exploitation requires user interaction, such as connecting to a malicious network, but no additional privileges. The flaw stems from missing checks in the modem firmware’s secure boot chain, enabling MitM attacks.
DailyCVE Form
Platform: MediaTek Modem
Version: Pre-MOLY01334347
Vulnerability: Certificate Validation Bypass
Severity: Critical
Date: 05/06/2025
What Undercode Say:
Exploitation
1. Rogue Base Station Setup:
sudo srsran --rf.device=uhd --rf.dl_freq=2140e6 --rf.ul_freq=1950e6 --rat=lte
2. SSL Stripping: Use tools like `sslstrip2` to downgrade HTTPS:
iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080 sslstrip -l 8080
Detection
1. Modem Firmware Check:
atcmd AT+SVN | grep "MOLY01334347"
2. Network Log Analysis:
journalctl -u NetworkManager | grep "certificate_verify_failed"
Mitigation
1. Patch Application:
mtkupdater --flash --firmware=latest_secure_boot.img
2. Network Restrictions:
nmcli con modify Cellular gsm.auto-config=no
Debugging
1. Modem Logs:
adb logcat | grep -i "modem_security"
2. Certificate Pin: Hardcode trusted CAs in modem config:
{ "trusted_cas": ["SHA256:ABC123..."] }
References
- MediaTek Advisory: MTK-MS-2772
- CVSS 4.0 Vector: `CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
