IoT
VPNFilter-affected Devices Still Riddled with 19 Bugs
This blog tackles the VPNFilter malware and if deployed devices are vulnerable to it. Based on our data, plenty of the devices are still using old firmware versions. In fact, 19 known vulnerabilities can still be detected in devices up to this day.
Our IoT scanning tool allows users to identify if connected devices (e.g. routers, network attached storage devices, IP cameras, and printers) in a given network are vulnerable to security risks and vulnerabilities, such as those related to Mirai, Reaper, and WannaCry.
We gather our data from the Trend Micro™ Home Network Security solution and HouseCall™ for Home Networks scanner. HouseCall for Home Networks is a free tool that features device recognition and vulnerability scanning in users' networks and connected devices. Home Network Security is a solution plugged into users’ routers that protects connected devices from potential cyberattacks. Our scanning can cover multiple operating systems, including Linux, Mac, Windows, Android, iOS, and other software development kit (SDK) platforms.
This blog tackles the recently ill-famed VPNFilter malware and if deployed devices are vulnerable to it and other vulnerabilities. VPNFilter is a newly discovered, multi-stage malware (detected by Trend Micro as ELF_VPNFILT.A, ELF_VPNFILT.B, ELF_VPNFILT.C, and ELF_VPNFILT.D) that affects many models of connected devices. Initially reported at the tail end of May to have infected at least 500,000 networking devices across 54 countries, including those from Linksys, MikroTik, Netgear, and TP-Link, to steal website credentials and even render devices unusable, the malware is now seen targeting more devices to deliver exploits and even override reboots. The Federal Bureau of Investigation (FBI) has even released a public service announcement (PSA), warning that it is the work of foreign threat actors looking to compromise networked devices worldwide.
Different brands and models affected by VPNFilter and more
VPNFilter is known to affect over ten brands and 70 models of devices. Our IoT scanning tool can identify other publicly known vulnerabilities targeting the devices as listed below:
| Manufacturer | Model | Device Type |
| Asus | RT-AC66U, RT-N10, RT-N10E, RT-N10U, RT-N56U, and RT-N66U | Routers |
| D-Link | DES-1210-08P DIR-300, DIR-300A, DSR-250N, DSR-500N, DSR-1000, and DSR-1000N | Ethernet switch Routers |
| Huawei | HG8245 | Router |
| Linksys | E1200, E2500, E3000 E3200, E4200, RV082, and WRVS4400N | Routers |
| MikroTik | CCR1009, CCR1016, CCR1036, CCR1072, CRS109, CRS112, CRS125, RB411, RB450, RB750, RB911, RB921, RB941, RB951, RB952, RB960, RB962, RB1100, RB1200, RB2011, RB3011, RB Groove, RB Omnitik, and STX5 | Routers |
| Netgear | DG834, DGN1000, DGN2200, DGN3500, FVS318N, MBRN3000, R6400, R7000, R8000, WNR1000, WNR2000, WNR2200, WNR4000, WNDR3700, WNDR4000, WNDR4300, WNDR4300-TN, and UTM50 | Routers |
| QNAP | TS251, TS439 Pro, and other QNAP NAS devices running QTS software | NAS devices |
| TP-Link | R600VPN, TL-WR741ND, and TL-WR841N | Routers |
| Ubiquiti | NSM2 and PBE M5 | Wireless access points |
| ZTE | ZXHN H108N | Router |
Table 1. Some of the known affected devices by VPNFilter
Based on our data from June 1 to July 12, plenty of the devices are still using old firmware versions. In fact, 19 known vulnerabilities, not only taken advantage of by VPNFilter but other malware as well, can still be detected in devices up to this day.
At the time of our scanning, we observed that 34 percent of home networks had at least one device with a known vulnerability. We found that 9 percent of vulnerable devices are potentially affected by VPNFilter.
| Device Vulnerabilities | Vulnerable Devices/Services |
| Authentication Bypass Vulnerability CVE-2015-7261 | QNAP FTP Service |
| Reaper Remote Code Execution CVE-2011-4723 | D-Link DIR-300 |
| Remote Code Execution CVE-2014-9583 | ASUS RT-AC66U, RT-N66U |
| Reaper OS Command Injection CVE-2013-2678 | Linksys E2500 |
| Buffer Overflow Vulnerability CVE-2013-0229 | Vulnerable UPnP Service (e.g. Netgear/TP-Link/D-Link) |
| Stack Overflow Vulnerability CVE-2013-0230 | Vulnerable UPnP Service (e.g. Netgear/TP-Link/D-Link) |
| Remote Code Execution CVE-2017-6361 | QNAP QTS before 4.2.4 Build 20170313 |
| Router JSONP Info Leak CVE-2017-8877 | ASUS RT-AC* and RT-N* |
| Router Password Disclosure CVE-2017-5521 | Netgear R6400, R7000, R8000 |
| Stack Overflow Vulnerability CVE-2012-5958 | Vulnerable UPnP Service (e.g. Netgear/TP-Link/D-Link) |
| Stack Overflow Vulnerability CVE-2012-5959 | Vulnerable UPnP Service (e.g. Netgear/TP-Link/D-Link) |
| Reaper Router Remote Code Execution | D-Link DIR-300 |
| Router Password Disclosure | Netgear WNR2000 |
| Remote Code Execution CVE-2016-6277 | Netgear R6400, R7000 |
| Router Session Stealing CVE-2017-6549 | ASUS RT-N66U |
| OS Command Injection CVE-2013-2679 | Linksys E4200 |
| Authentication Bypass Vulnerability | Netgear WNR1000 |
| Router Password Disclosure | Netgear WNR1000 |
| Unauthenticated Router Access Vulnerability | TP-Link TL-WR841N |
Table 2. 19 vulnerability detections on VPNFilter-affected devices
As expected, the 19 vulnerabilities primarily affect routers. Interestingly, the Authentication Bypass Vulnerability CVE-2015-7261, an FTP (File Transfer Protocol) flaw in the QNAP NAS firmware, mostly affects printers based on our detection. While determining the possible reason behind this, we found that many of the detected printers’ FTP could connect to the network without any authentication. In some cases, this may be the printer’s default configuration, but it still poses a potential security risk if the FTP is set as open on the internet.
Figure 1. A Shodan result of an FTP connection to a printer without authentication
The other vulnerabilities detected, such as the Buffer Overflow CVE-2013-0229 and Stack Overflow CVE-2013-0230, can allow attackers to cause a denial-of-service (DoS) and execute arbitrary code in systems, respectively. Vulnerable UPnP Services detected, moreover, aren’t exclusively associated with Netgear/TP-Link/D-Link devices, as other brands could also have the same vulnerability. In that case, we can expect more detections.
Protecting devices and networks against VPNFilter malware and other vulnerabilities
The threat of VPNFilter malware is augmented by the fact that other publicly known vulnerabilities were detected in the affected devices. Since not all device manufacturers provide immediate fixes for discovered vulnerabilities and not all users regularly apply patches, users should first secure the way they set up their devices and networks. Trend Micro™ Home Network Security solution can check internet traffic between the router and all connected devices. Our IoT scanning tool has been integrated into the Home Network Security solution and HouseCall™ for Home Networks scanner. Enterprises can also monitor all ports and network protocols for advanced threats and thwart targeted attacks with the Trend Micro™ Deep Discovery™ Inspector network appliance.
Aside from adopting security solutions that can protect networks and connected devices from the vulnerabilities through the identification and assessment of potential risks, we recommend standard security measures, such as:
- Updating the firmware versions of devices once they’re available to avoid attacks that exploit known vulnerabilities.
- Avoiding the use of public Wi-Fi on devices that are also used in home or corporate networks.
- Changing device’s default credentials and using strong passwords to deter unauthorized access.
- Being wary of suspicious URLs or attachments from unknown sources that may lead to infecting devices connected to the network.
Users of the Trend Micro Home Network Security solution are also protected from particular vulnerabilities via these rules:
- 1058981 WEB Directory Traversal -21
- 1130327 EXPLOIT ASUSWRT 3.0.0.4.376_1071 LAN Backdoor Command Execution (CVE-2014-9583)