Almost immediately after being disclosed publicly, a vulnerability with routers running Arcadyan firmware has been exploited by hackers, potentially affecting millions of home routers.

Although this vulnerability was disclosed to router manufacturers in April, it was made public on August 3. There have been reports of hackers actively attacking these compromised routers since.

What is the issue?

The vulnerability, referred to as CVE-2021-20090, is a critical path traversal vulnerability in the web interfaces of routers with Arcadyan firmware. The vulnerability allows remote attackers to bypass authentication. This makes it possible for attackers to deploy Mirai botnet malicious payloads to affected devices.

Why should I be concerned?

This vulnerability can allow an unauthenticated remote attacker to take control of connected devices. Once this happens, the attacker can:

• Manipulate your internet traffic
• Gain access to sensitive information on your devices
• Alter router settings to make your network more vulnerable

Because not a lot of people are even aware of this security risk and people do not change their routers very frequently, this vulnerability presents a very serious problem for many.

How to check if your router is affected

Here is the list of confirmed devices affected by this vulnerability:

Manufacturer	Device Model	Affected Firmware Version
ADB	ADSL wireless IAD router	1.26S-R-3P
Arcadyan	ARV7519	00.96.00.96.617ES
Arcadyan	ARV7519	00.96.00.96.617ES
Arcadyan	VRV9517	6.00.17 build04
Arcadyan	VGV7519	3.01.116
Arcadyan	VRV9518	1.01.00 build44
ASMAX	BBR-4MG / SMC7908 ADSL	0.08
ASUS	DSL-AC88U (Arc VRV9517)	1.10.05 build502
ASUS	DSL-AC87VG (Arc VRV9510)	1.05.18 build305
ASUS	DSL-AC3100	1.10.05 build503
ASUS	DSL-AC68VG	5.00.08 build272
Beeline	Smart Box Flash	1.00.13_beta4
British Telecom	WE410443-SA	1.02.12 build02
Buffalo	WSR-2533DHPL2	1.02
Buffalo	WSR-2533DHP3	1.24
Buffalo	BBR-4HG
Buffalo	BBR-4MG	2.08 Release 0002
Buffalo	WSR-3200AX4S	1.1
Buffalo	WSR-1166DHP2	1.15
Buffalo	WXR-5700AX7S	1.11
Deutsche Telekom	Speedport Smart 3	010137.4.8.001.0
HughesNet	HT2000W	0.10.10
KPN	ExperiaBox V10A (Arcadyan VRV9517)	5.00.48 build453
KPN	VGV7519	3.01.116
O2	HomeBox 6441	1.01.36
Orange	LiveBox Fibra (PRV3399)	00.96.00.96.617ES
Skinny	Smart Modem (Arcadyan VRV9517)	6.00.16 build01
SparkNZ	Smart Modem (Arcadyan VRV9517)	6.00.17 build04
Telecom (Argentina)	Arcadyan VRV9518VAC23-A-OS-AM	1.01.00 build44
TelMex	PRV33AC	1.31.005.0012
TelMex	VRV7006
Telstra	Smart Modem Gen 2 (LH1000)	0.13.01r
Telus	WiFi Hub (PRV65B444A-S-TS)	v3.00.20
Telus	NH20A	1.00.10debug build06
Verizon	Fios G3100	2.0.0.6
Vodafone	EasyBox 904	4.16
Vodafone	EasyBox 903	30.05.714
Vodafone	EasyBox 802	20.02.226

For more information, visit Tenable.

Secure Your Wi-Fi Router and Protect Your Home Network

Affected users should contact their respective vendors for update information and support. Ideally, a resolution will be available for all soon. However, this won’t stop hackers and threat actors from forever seeking new ways to compromise people’s security. To ensure your home network stays protected use Trend Micro Home Network Security.

The Home Network Security station is a device that connects to your home Wi-Fi router with an Ethernet cable. Once setup is complete, the station scans all traffic passing in and out of your home network, allowing it to prevent intrusions, block hacking attempts and web threats as well as protect your family’s privacy.

Home Network Security provides your home network with an essential extra layer of protection. Click the button below to learn more: