CVE-2021-35393 : Security Advisory and Response

Realtek Jungle SDK version v2.x up to v3.4.14B contains a critical vulnerability in the 'WiFi Simple Config' server, allowing remote unauthenticated attackers to execute arbitrary code on the affected device.

Understanding CVE-2021-35393

This section will delve into the specifics of CVE-2021-35393.

What is CVE-2021-35393?

The Realtek Jungle SDK, specifically versions v2.x to v3.4.14B, encompasses a vulnerable 'WiFi Simple Config' server that mishandles UPnP SUBSCRIBE/UNSUBSCRIBE Callback headers, leading to a stack buffer overflow flaw. Upon successful exploitation, malicious actors can achieve arbitrary code execution remotely.

The Impact of CVE-2021-35393

The vulnerability in the Realtek Jungle SDK could result in severe consequences, granting unauthorized individuals the ability to execute arbitrary code on the targeted device without authentication.

Technical Details of CVE-2021-35393

Let's explore the technical aspects related to CVE-2021-35393.

Vulnerability Description

The stack buffer overflow vulnerability arises from the insecure parsing of UPnP SUBSCRIBE/UNSUBSCRIBE Callback headers in the 'WiFi Simple Config' server of Realtek Jungle SDK versions v2.x up to v3.4.14B.

Affected Systems and Versions

All systems utilizing Realtek Jungle SDK versions v2.x through v3.4.14B with the 'WiFi Simple Config' server enabled are susceptible to this vulnerability.

Exploitation Mechanism

Remote, unauthenticated attackers can exploit this vulnerability by sending specifically crafted UPnP SUBSCRIBE/UNSUBSCRIBE Callback headers to trigger a stack buffer overflow and subsequently execute arbitrary code on the vulnerable device.

Mitigation and Prevention

Learn how to mitigate and prevent the exploitation of CVE-2021-35393.

Immediate Steps to Take

Immediately disable the 'WiFi Simple Config' server or update to a patched version of Realtek Jungle SDK to safeguard against this vulnerability. Network segmentation and access controls can also help mitigate the risk.

Long-Term Security Practices

Incorporate secure coding practices, regular security assessments, and timely software updates to establish a robust security posture and prevent similar vulnerabilities in the future.

Patching and Updates

Regularly monitor Realtek's security advisories and promptly apply patches for the Jungle SDK to address known vulnerabilities and enhance the security of your systems.