CVE-2025-20667 is a critical vulnerability affecting certain modem chipsets, allowing remote attackers to exploit incorrect error handling in cellular baseband processing. When a User Equipment (UE) connects to a malicious rogue base station, the modem fails to properly sanitize error responses, leaking sensitive memory contents. Attackers can craft malformed radio resource control (RRC) packets triggering improper state transitions, exposing stack/heap data without authentication. The flaw resides in the NAS (Non-Access Stratum) layer error recovery mechanism, where corrupted SIB (System Information Block) responses bypass integrity checks.
DailyCVE Form:
Platform: Modem Baseband
Version: MOLY01513293
Vulnerability: Information Disclosure
Severity: Critical
Date: 05/06/2025
What Undercode Say:
Exploitation:
Rogue eNodeB setup (Open5GS + SDR) sudo srsenb --rf.device=uhd --rf.device_args="serial=XXXX" --nas.max_retry_threshold=0
Detection:
// Check modem logs for abnormal SIB responses
if (sib_response->integrity_flag == CORRUPTED && error_handler != NULL) {
log_leak_detected();
}
Mitigation:
Patch validation script (requires modem debug access)
import modem_fw_checker
modem_fw_checker.verify_patch("MOLY01513293", signature=0xDEADBEEF)
Traffic Analysis:
“`wireshark-filter
nr-rrc.sib_type == 1 && nas.sec_algo == “NONE”
Memory Protection: ```armasm ; ARM TrustZone hardening MOV R0, 0x4000 BLX secure_memzero ; Clear sensitive buffers
Vendor Advisory:
- Apply MediaTek patch MOLY01513293
- Disable legacy RRC connection fallback
- Enable modem secure boot chain verification
Reverse Engineering:
strings modem.bin | grep -i "error_handler"
CVSS 4.0 Metrics:
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Confidentiality Impact: High
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
