CVE-2021-3128

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.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 2.48% Top 20%
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Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX3000/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-WiFi-Systems/ASUS-ZenWiFi-AX-XT8-/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX88U/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX86U/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX82U/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX68U/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX58U/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX56U/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX55/HelpDesk_BIOS/ product vendor advisory
https://www.asus.com/supportonly/RT-AC5300/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC88U/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC3100/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC86U/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC2900/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC1750_B1/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC1900/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC1900P/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC1900U/HelpDesk_download/ product vendor advisory
https://www.asus.com/Networking-IoT-Servers/WiFi-Routers/ASUS-WiFi-Routers/RT-AC66U-B1/HelpDesk_Download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC68P/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC68R/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC68RW/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC68U/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC58U/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC85U/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC65U/HelpDesk_download/ product vendor advisory
https://www.asus.com/supportonly/RT-AC68W/HelpDesk_download/ product vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-3128?
CVE-2021-3128 has been scored as a high severity vulnerability.
How to fix CVE-2021-3128?
To fix CVE-2021-3128, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-3128 being actively exploited in the wild?
It is possible that CVE-2021-3128 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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