SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-3128

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…

HIGH 7.5EPSS 2.18%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
2.18% probability · 81th percentile
CISA KEV
Not listed
Weakness
CWE-834
Affected
asus/zenwifi ax \(xt8\) firmware · asus/rt-ax3000 firmware · asus/rt-ax55 firmware · asus/rt-ax56u firmware · asus/rt-ax58u firmware · asus/rt-ax68u firmware · asus/rt-ax82u firmware · asus/rt-ax86u firmware · asus/rt-ax88u firmware · asus/rt-ac66u b1 firmware · asus/rt-ac1750 b1 firmware · asus/rt-ac1900 firmware · asus/rt-ac1900p firmware · asus/rt-ac1900u firmware · asus/rt-ac2900 firmware · asus/rt-ac3100 firmware · asus/rt-ac5300 firmware · asus/rt-ac58u firmware · asus/rt-ac65u firmware · asus/rt-ac68p firmware · +7 more
Source
cve@mitre.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.