How the CVE Works:
CVE-2025-29387 is a critical stack overflow vulnerability in Tenda AC9 routers, specifically in version v1.0 V15.03.05.14_multi. The flaw resides in the `wanSpeed` parameter of the `/goform/AdvSetMacMtuWan` endpoint. When an attacker sends a specially crafted HTTP request with an oversized `wanSpeed` value, it triggers a stack overflow. This overflow can overwrite critical memory regions, allowing the attacker to execute arbitrary code remotely. The vulnerability is exploitable without authentication, making it highly dangerous. Successful exploitation could grant the attacker full control over the router, enabling them to manipulate network traffic, steal sensitive data, or deploy malware.
DailyCVE Form:
Platform: Tenda AC9
Version: v1.0 V15.03.05.14_multi
Vulnerability: Stack Overflow
Severity: Critical
Date: 03/14/2025
What Undercode Say:
Exploitation:
1. Crafting the Payload:
- Use tools like `curl` or `Python` to send an HTTP POST request with an oversized `wanSpeed` parameter.
- Example Python code:
import requests url = "http://<router_ip>/goform/AdvSetMacMtuWan" payload = {"wanSpeed": "A" 1000} Overflow payload response = requests.post(url, data=payload) print(response.text)
2. Gaining Control:
- After triggering the overflow, inject shellcode into the stack to execute arbitrary commands.
- Use tools like `Metasploit` to automate exploitation:
msfconsole use exploit/linux/http/tenda_ac9_stack_overflow set RHOSTS <router_ip> exploit
Protection:
1. Patch Management:
- Check for firmware updates from Tenda and apply the latest patch immediately.
- Example command to check for updates:
curl -I http://<router_ip>/fwupdate
2. Network Hardening:
- Disable remote administration features on the router.
- Use a firewall to restrict access to the router’s management interface.
3. Input Validation:
- Implement input validation on the `wanSpeed` parameter to reject oversized values.
- Example code snippet:
if (strlen(wanSpeed) > 64) { return ERROR_INVALID_INPUT; }
4. Monitoring:
- Use intrusion detection systems (IDS) like Snort to detect exploitation attempts.
- Example Snort rule:
alert tcp any any -> $HOME_NET 80 (msg:"Tenda AC9 Stack Overflow Attempt"; content:"/goform/AdvSetMacMtuWan"; content:"wanSpeed"; depth:100;)
5. Mitigation:
- Enable stack protection mechanisms like ASLR (Address Space Layout Randomization) and DEP (Data Execution Prevention) if supported by the router’s firmware.
By following these steps, users can mitigate the risk of exploitation and secure their Tenda AC9 routers against CVE-2025-29387.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-29387
Extra Source Hub:
Undercode
