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CVE-2021-3128

High

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.

SeverityHigh
CVSS7.5
Exploit probability—
ProductAsus Zenwifi Ax \(xt8\) Firmware
PublishedApr 12, 2021
First seenApr 12, 2021

How to fix

Update
  • asus zenwifi_ax_\(xt8\)_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax3000_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax55_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax56u_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax58u_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax68u_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax82u_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax86u_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ax88u_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ac66u_b1_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ac1750_b1_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later
  • asus rt-ac1900_firmware3.0.0.4.386.42095, 9.0.0.4.386.41994 or later

Affected products

ProductAffected versionsFixed in
asus zenwifi_ax_\(xt8\)_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax3000_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax55_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax56u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax58u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax68u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax82u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax86u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ax88u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac66u_b1_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac1750_b1_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac1900_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac1900p_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac1900u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac2900_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac3100_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac5300_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac58u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac65u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac68p_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac68r_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac68rw_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac68u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac68w_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac85u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac86u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994
asus rt-ac88u_firmwarev < 3.0.0.4.386.42095, v < 9.0.0.4.386.419943.0.0.4.386.42095, 9.0.0.4.386.41994

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