Latest Zyxel vulnerability #
GreyNoise has indicated that they are observing active exploitation against a previously unknown vulnerability in Zyxel CPE devices. This vulnerability has been assigned CVE-2024-40891.
There is indication that this vulnerability is being actively exploited in the wild.
What is the impact? #
Successful exploitation of this vulnerability would allow an attacker to execute arbitrary commands on the vulnerable device, potentially leading to complete system compromise.
Are updates or workarounds available? #
There is currently no update available that addresses this vulnerability. Users are recommended to disable the administrative interfaces on their Zyxel devices and allow connections to these devices only from trusted addresses.
How to find potentially vulnerable systems with runZero #
From the Asset Inventory, use the following query to locate systems running potentially vulnerable devices:
hw:"VMG1312-B10A" OR
hw:"VMG1312-B10B" OR
hw:"VMG1312-B10E" OR
hw:"VMG3312-B10A" OR
hw:"VMG3313-B10A" OR
hw:"VMG3926-B10B" OR
hw:"VMG4325-B10A" OR
hw:"VMG4380-B10A" OR
hw:"VMG8324-B10A" OR
hw:"VMG8924-B10A" OR
hw:"SBG3300" OR
hw:"SBG3500"CVE-2024-7261 (September 2024) #
In September 2024, Zyxel disclosed a vulnerability in several Zyxel Wireless Access Point (WAP) and router devices. A vulnerability in the handling of cookies sent via HTTP requests could allow an unauthenticated attacker to execute arbitrary code on the vulnerable system.
This vulnerability was designated CVE-2024-7261 and was rated extremely critical with a CVSS score of 9.8.
What was the impact? #
Successful exploitation of these vulnerabilities resulted in devices allowing attackers to perform remote code execution (RCE) by sending a specially crafted cookie to the vulnerable device.
Zyxel released firmware updates that addressed these vulnerabilities and urged all users to update as quickly as possible.
How runZero users found potentially vulnerable Zyxel firmware #
runZero users visited the Asset Inventory, and use the following query to locate systems running potentially vulnerable Zyxel firmware:
hw:ZyxelCVE-2023-28771 (April 2023) #
In April 2023, Zyxel disclosed a remote command execution vulnerability affecting a handful of their product families. This vulnerability was assigned CVE-2023-28771, and with a CVSSv3 score of 9.8, this vulnerability was considered highly critical. Attackers who sent a specially crafted packet to UDP port 500 on an affected Zyxel device could execute arbitrary commands or create a denial-of-service condition.
Along with this disclosure, Zyxel announced updated software to address this issue; information about the update is available here.
There were reports that this vulnerability was being actively exploited in the wild. In the device's default configuration, the vulnerable port is often exposed to the public Internet.
How runZero users found affected devices #
runZero users located Zyxel devices by visiting the Asset Inventory and using the following pre-built query:
hw:"Zyxel" and udp_port:500
The devices found by this query should be checked to make sure they are running a patched version of their firmware.
As always, any prebuilt queries we create are available from our Queries Library. Check out the library for other useful inventory queries.
