CVE-2021-3128
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 16.2% chance of exploitation in the next 30 days (EPSS). Higher than most.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 16.2% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 16.2% · EPSS, next 30 days
- Weakness
- CWE-834
- Record status
- Modified
Affected
- Asus Zenwifi Ax \(xt8\) Firmware < 3.0.0.4.386.42095
- Asus Zenwifi Ax \(xt8\) Firmware < 9.0.0.4.386.41994
- Asus rt-ax3000 Firmware < 3.0.0.4.386.42095
- Asus rt-ax3000 Firmware < 9.0.0.4.386.41994
- Asus rt-ax55 Firmware < 3.0.0.4.386.42095
- Asus rt-ax55 Firmware < 9.0.0.4.386.41994
- Asus rt-ax56u Firmware < 3.0.0.4.386.42095
- Asus rt-ax56u Firmware < 9.0.0.4.386.41994
Attack profile CVSS 3.1 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-3128.md and follow it. Check whether this project is affected by CVE-2021-3128. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://www.asus.com/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-WiFi-Systems/ASUS-ZenWiFi-AX-XT8-/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX3000/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX55/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX56U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX58U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX68U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX82U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX86U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX88U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-Routers/ASUS-WiFi-Routers/RT-AC66U-B1/HelpDesk_Download/
References
- https://www.asus.com/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-WiFi-Systems/ASUS-ZenWiFi-AX-XT8-/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX3000/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX55/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX56U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX58U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX68U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX82U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX86U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-6/All-series/RT-AX88U/HelpDesk_BIOS/
- https://www.asus.com/Networking-IoT-Servers/WiFi-Routers/ASUS-WiFi-Routers/RT-AC66U-B1/HelpDesk_Download/
- https://www.asus.com/supportonly/RT-AC1750_B1/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC1900/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC1900P/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC1900U/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC2900/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC3100/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC5300/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC58U/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC65U/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC68P/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC68R/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC68RW/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC68U/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC68W/HelpDesk_download/
- https://www.asus.com/supportonly/RT-AC85U/HelpDesk_download/