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How the CVE Works:
CVE-2025-29029 is a critical buffer overflow vulnerability found in Tenda AC6 routers running firmware version v15.03.05.16. The flaw resides in the `formSetSpeedWan` function, which improperly handles user-supplied input. Attackers can exploit this by sending a specially crafted request to the router, causing a buffer overflow. This overflow can overwrite adjacent memory, potentially allowing remote code execution (RCE) or a denial-of-service (DoS) condition. The vulnerability is particularly dangerous as it can be exploited remotely without authentication, making it a high-priority threat for affected users.
DailyCVE Form:
Platform: Tenda AC6
Version: v15.03.05.16
Vulnerability: Buffer Overflow
Severity: Critical
Date: 03/14/2025
What Undercode Say:
Exploitation:
1. Crafting the Payload:
Attackers can craft a malicious payload that exceeds the buffer size in the `formSetSpeedWan` function. This payload is sent via a HTTP POST request to the router’s web interface.
Example:
curl -X POST -d "param=OVERFLOW_PAYLOAD" http://<router_ip>/goform/SetSpeedWan
2. Gaining Control:
By overwriting the return address in the stack, attackers can redirect execution to their injected shellcode, enabling remote code execution.
3. Post-Exploitation:
Once exploited, attackers can install backdoors, modify router settings, or launch further attacks on the network.
Protection:
1. Patch Management:
Update the router firmware to the latest version provided by Tenda.
2. Input Validation:
Implement strict input validation in the `formSetSpeedWan` function to prevent buffer overflows.
3. Network Segmentation:
Isolate the router from critical internal networks to limit the impact of potential exploitation.
4. Firewall Rules:
Restrict access to the router’s web interface using firewall rules. Only allow trusted IPs to interact with the interface.
5. Monitoring:
Use intrusion detection systems (IDS) to monitor for unusual traffic patterns or exploit attempts.
Example Code for Input Validation:
void formSetSpeedWan(char input) {
char buffer[bash];
if (strlen(input) < sizeof(buffer)) {
strncpy(buffer, input, sizeof(buffer) - 1);
buffer[bash] = '\0';
} else {
// Handle error: input too large
return;
}
// Process input
}
Analytics:
- CVSS Score: 9.8 (Critical)
- Attack Vector: Network
- Exploitability: High
- Impact: Complete system compromise
Commands for Mitigation:
1. Check Firmware Version:
cat /etc/firmware_version
2. Block Unauthorized Access:
iptables -A INPUT -p tcp --dport 80 -s ! <trusted_ip> -j DROP
3. Monitor Logs:
tail -f /var/log/router.log
By following these steps, users can mitigate the risks associated with CVE-2025-29029 and protect their Tenda AC6 routers from exploitation.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-29029
Extra Source Hub:
Undercode
