CVE-2018-18731 Explained : Impact and Mitigation

A security flaw was found on certain models of Tenda routers, leading to a buffer overflow vulnerability in the router's web server.

Understanding CVE-2018-18731

What is CVE-2018-18731?

This CVE identifies a vulnerability in Tenda routers where the 'deviceMac' parameter in a post request can trigger a buffer overflow due to improper handling in the httpd component.

The Impact of CVE-2018-18731

The vulnerability allows attackers to override the function's return address, potentially leading to remote code execution or denial of service.

Technical Details of CVE-2018-18731

Vulnerability Description

The issue arises from the direct utilization of the 'deviceMac' parameter in a sprintf function, causing a buffer overflow vulnerability.

Affected Systems and Versions

Tenda routers AC7 V15.03.06.44_CN
AC9 V15.03.05.19(6318)_CN
AC10 V15.03.06.23_CN
AC15 V15.03.05.19_CN
AC18 V15.03.05.19(6318)_CN

Exploitation Mechanism

The vulnerability occurs when processing the 'deviceMac' parameter in a post request, leading to the overriding of the function's return address.

Mitigation and Prevention

Immediate Steps to Take

Apply patches or updates provided by Tenda to fix the vulnerability.
Restrict network access to the router to trusted devices only.

Long-Term Security Practices

Regularly update router firmware to address security issues.
Implement network segmentation to isolate critical devices from potential attacks.
Monitor network traffic for any suspicious activities.

Patching and Updates

Ensure to regularly check for firmware updates from Tenda and apply them promptly to mitigate the CVE-2018-18731 vulnerability.