Vulnerability Description
In ASUS RT-AX3000, ZenWiFi AX (XT8), RT-AX88U, and other ASUS routers with firmware < 3.0.0.4.386.42095 or < 9.0.0.4.386.41994, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Asus | Zenwifi Ax \(Xt8\) Firmware | < 3.0.0.4.386.42095 |
| Asus | Zenwifi Ax \(Xt8\) | - |
| Asus | Rt-Ax3000 Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax3000 | - |
| Asus | Rt-Ax55 Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax55 | - |
| Asus | Rt-Ax56U Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax56U | - |
| Asus | Rt-Ax58U Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax58U | - |
| Asus | Rt-Ax68U Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax68U | - |
| Asus | Rt-Ax82U Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax82U | - |
| Asus | Rt-Ax86U Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax86U | - |
| Asus | Rt-Ax88U Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ax88U | - |
| Asus | Rt-Ac66U B1 Firmware | < 3.0.0.4.386.42095 |
| Asus | Rt-Ac66U B1 | - |
Related Weaknesses (CWE)
References
- https://www.asus.com/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX3000/HelpDeskProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX55/HelpDesk_BProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX56U/HelpDesk_ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX58U/HelpDesk_ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX68U/HelpDesk_ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX82U/HelpDesk_ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX86U/HelpDesk_ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX88U/HelpDesk_ProductVendor Advisory
- https://www.asus.com/Networking-IoT-Servers/WiFi-Routers/ASUS-WiFi-Routers/RT-ACProductVendor Advisory
- https://www.asus.com/supportonly/RT-AC1750_B1/HelpDesk_download/ProductVendor Advisory
- https://www.asus.com/supportonly/RT-AC1900/HelpDesk_download/ProductVendor Advisory
- https://www.asus.com/supportonly/RT-AC1900P/HelpDesk_download/ProductVendor Advisory
- https://www.asus.com/supportonly/RT-AC1900U/HelpDesk_download/ProductVendor Advisory
- https://www.asus.com/supportonly/RT-AC2900/HelpDesk_download/ProductVendor Advisory
FAQ
What is CVE-2021-3128?
CVE-2021-3128 is a vulnerability with a CVSS score of 7.5 (HIGH). In ASUS RT-AX3000, ZenWiFi AX (XT8), RT-AX88U, and other ASUS routers with firmware < 3.0.0.4.386.42095 or < 9.0.0.4.386.41994, when IPv6 is used, a routing loop can occur that generates excessive net...
How severe is CVE-2021-3128?
CVE-2021-3128 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-3128?
Check the references section above for vendor advisories and patch information. Affected products include: Asus Zenwifi Ax \(Xt8\) Firmware, Asus Zenwifi Ax \(Xt8\), Asus Rt-Ax3000 Firmware, Asus Rt-Ax3000, Asus Rt-Ax55 Firmware.