Vulnerabilities Affecting Over One Million Dasan GPON Routers Are Now Under Attack
Two vulnerabilities affecting over one million routers, and disclosed earlier this week, are now under attack by botnet herders, who are trying to gather the vulnerable devices under their control. Exploitation of these two flaws started after on Monday, April 30, an anonymous researcher published details of the two vulnerabilities via the VPNMentor blog.
His findings detail two flaws —an authentication bypass (CVE-2018-10561) and a remote code execution vulnerability (CVE-2018-10562). The most ludicrous of these two flaws is the first, which basically allows anyone to access the router's internal settings by appending the "?images" string to any URL, effectively giving anyone control over the router's configuration. By combining these two issues, the anonymous researcher said he was able to bypass authentication and execute code on vulnerable devices. A video by the VPNMentor crew summarizes the findings.
Within just 10 days of the disclosure of two critical vulnerabilities in GPON router at least 5 botnet families have been found exploiting the flaws to build an army of million devices. Security researchers from Chinese-based cybersecurity firm Qihoo 360 Netlab have spotted 5 botnet families, including Mettle, Muhstik, Mirai, Hajime, and Satori, making use of the GPON exploit in the wild.
Even if there is no official patch available, users can protect their devices by disabling remote administration and using a firewall to prevent outside access from the public Internet. Making these changes to your vulnerable router would restrict access to the local network only, within the range of your Wi-Fi network, effectively reducing the attack surface by eliminating remote attackers.
If you are unsure about these settings, vpnMentor has done this job for you by providing an online "user-friendly" solution that automatically modifies your router settings on your behalf, keeping you away from remote attacks.