CVE-2021-3128 : Security Advisory and Response
Get insights into CVE-2021-3128, a vulnerability affecting ASUS routers leading to routing loops and excessive network traffic. Learn about the impact, technical details, affected systems, and mitigation steps.
This article provides detailed information about CVE-2021-3128, a vulnerability affecting ASUS routers that can lead to a routing loop and excessive network traffic.
Understanding CVE-2021-3128
This section delves into the specific details of the CVE-2021-3128 vulnerability.
What is CVE-2021-3128?
The CVE-2021-3128 vulnerability impacts ASUS RT-AX3000, ZenWiFi AX (XT8), RT-AX88U, and other ASUS routers with specific firmware versions. It can trigger a routing loop when IPv6 is used, causing increased network traffic.
The Impact of CVE-2021-3128
The vulnerability can result in the generation of excessive network traffic between the affected ASUS router and its upstream ISP's router. This occurs due to a routing loop that affects the network communication.
Technical Details of CVE-2021-3128
This section details the technical aspects of the CVE-2021-3128 vulnerability.
Vulnerability Description
When a link prefix route points to a point-to-point link and a router advertisement is received with specific conditions, a routing loop can be triggered in ASUS routers.
Affected Systems and Versions
ASUS routers with firmware versions lower than 3.0.0.4.386.42095 or 9.0.0.4.386.41994 are vulnerable to CVE-2021-3128, especially when IPv6 is utilized.
Exploitation Mechanism
The vulnerability manifests when a destination IPv6 address belongs to a prefix, is not a local IPv6 address, and certain conditions in router advertisements are met.
Mitigation and Prevention
This section focuses on the steps to mitigate and prevent the exploitation of CVE-2021-3128.
Immediate Steps to Take
Users should update their ASUS router firmware to versions higher than 3.0.0.4.386.42095 or 9.0.0.4.386.41994 to address the vulnerability and prevent the occurrence of routing loops.
Long-Term Security Practices
Regularly updating router firmware, monitoring for security advisories, and ensuring proper network configurations are essential for maintaining a secure network environment.
Patching and Updates
ASUS provides patches and updates for various router models to address vulnerabilities like CVE-2021-3128. Users are advised to regularly check for firmware updates and apply them promptly.