high
7.5
CWE
834
Advisory Published
Updated

CVE-2021-3128

First published: Mon Apr 12 2021(Updated: )

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.

Credit: cve@mitre.org

Affected SoftwareAffected VersionHow to fix
ASUS ZenWiFi AX (xt8) Firmware<3.0.0.4.386.42095
ASUS ZenWiFi AX (xt8)
ASUS ZenWiFi AX (xt8) Firmware<9.0.0.4.386.41994
ASUS TUF Gaming AX3000 V2 Firmware<3.0.0.4.386.42095
ASUS routers
ASUS TUF Gaming AX3000 V2 Firmware<9.0.0.4.386.41994
ASUS RT-AX55 Firmware<3.0.0.4.386.42095
ASUS routers
ASUS RT-AX55 Firmware<9.0.0.4.386.41994
ASUS RT-AX56U V2 firmware<3.0.0.4.386.42095
ASUS RT-AX56U firmware
ASUS RT-AX56U V2 firmware<9.0.0.4.386.41994
ASUS RT-AX58U Firmware<3.0.0.4.386.42095
ASUS RT-AX58U Firmware
ASUS RT-AX58U Firmware<9.0.0.4.386.41994
ASUS RT-AX68U<3.0.0.4.386.42095
ASUS RT-AX68U Firmware
ASUS RT-AX68U<9.0.0.4.386.41994
Asus RT-AX82U firmware<3.0.0.4.386.42095
Asus RT-AX82U firmware
Asus RT-AX82U firmware<9.0.0.4.386.41994
ASUS RT-AX86U ZAKU II EDITION firmware<3.0.0.4.386.42095
ASUS RT-AX86
ASUS RT-AX86U ZAKU II EDITION firmware<9.0.0.4.386.41994
ASUS RT-AX88U Firmware<3.0.0.4.386.42095
ASUS RT-AX88U Firmware
ASUS RT-AX88U Firmware<9.0.0.4.386.41994
ASUS RT-AC66U B1<3.0.0.4.386.42095
ASUS RT-AC66U firmware
ASUS RT-AC66U B1<9.0.0.4.386.41994
ASUS RT-AC1750 firmware<3.0.0.4.386.42095
ASUS RT-AC1750
ASUS RT-AC1750 firmware<9.0.0.4.386.41994
ASUS RT-AC1900U Firmware<3.0.0.4.386.42095
ASUS RT-AC1900 Firmware
ASUS RT-AC1900U Firmware<9.0.0.4.386.41994
ASUS RT-AC1900P Firmware<3.0.0.4.386.42095
ASUS RT-AC1900P Firmware
ASUS RT-AC1900P Firmware<9.0.0.4.386.41994
ASUS RT-AC1900 Firmware<3.0.0.4.386.42095
ASUS RT-AC1900U Firmware
ASUS RT-AC1900 Firmware<9.0.0.4.386.41994
ASUS ROG Rapture GT-AC2900 Firmware<3.0.0.4.386.42095
ASUS RT-AC2900 firmware
ASUS ROG Rapture GT-AC2900 Firmware<9.0.0.4.386.41994
ASUS RT-AC3100 Firmware<3.0.0.4.386.42095
ASUS RT-AC3100
ASUS RT-AC3100 Firmware<9.0.0.4.386.41994
ASUS RT-AC5300 firmware<3.0.0.4.386.42095
ASUS RT-AC5300 firmware
ASUS RT-AC5300 firmware<9.0.0.4.386.41994
ASUS RT-AC58U firmware<3.0.0.4.386.42095
ASUS RT-AC58U firmware
ASUS RT-AC58U firmware<9.0.0.4.386.41994
ASUS RT-AC65U Firmware<3.0.0.4.386.42095
ASUS RT-AC65U Firmware
ASUS RT-AC65U Firmware<9.0.0.4.386.41994
ASUS RT-AC68P Firmware<3.0.0.4.386.42095
ASUS RT-AC68P Firmware
ASUS RT-AC68P Firmware<9.0.0.4.386.41994
ASUS RT-AC68R<3.0.0.4.386.42095
ASUS RT-AC68R Firmware
ASUS RT-AC68R<9.0.0.4.386.41994
ASUS RT-AC68RW<3.0.0.4.386.42095
ASUS RT-AC68RW Firmware
ASUS RT-AC68RW<9.0.0.4.386.41994
ASUS RT-AC68R<3.0.0.4.386.42095
ASUS 4G-AC68U
ASUS RT-AC68R<9.0.0.4.386.41994
ASUS RT-AC68W Firmware<3.0.0.4.386.42095
ASUS RT-AC68W
ASUS RT-AC68W Firmware<9.0.0.4.386.41994
ASUS RT-AC85U Firmware<3.0.0.4.386.42095
ASUS RT-AC85U Firmware
ASUS RT-AC85U Firmware<9.0.0.4.386.41994
ASUS RT-AC86U Firmware<3.0.0.4.386.42095
ASUS RT-AC86U firmware
ASUS RT-AC86U Firmware<9.0.0.4.386.41994
ASUS RT-AC88U Firmware<3.0.0.4.386.42095
ASUS RT-AC88U Firmware
ASUS RT-AC88U Firmware<9.0.0.4.386.41994

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-3128?

    CVE-2021-3128 is considered a high-severity vulnerability due to the potential for significant network disruption.

  • How do I fix CVE-2021-3128?

    To fix CVE-2021-3128, update your ASUS router firmware to versions 3.0.0.4.386.42095 or later, or 9.0.0.4.386.41994 or later.

  • Which ASUS router models are affected by CVE-2021-3128?

    CVE-2021-3128 affects various ASUS routers including RT-AX3000, ZenWiFi AX (XT8), and RT-AX88U with outdated firmware.

  • What type of issue does CVE-2021-3128 cause in affected routers?

    CVE-2021-3128 can cause a routing loop that leads to excessive network traffic and potential service interruptions.

  • Is CVE-2021-3128 an IPv6 related vulnerability?

    Yes, CVE-2021-3128 specifically triggers a vulnerability when IPv6 is used in the affected ASUS routers.

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