Attackers actively targeting vulnerable Dasan GPON home routers

SonicWall Capture Labs threat research team observed attacks exploiting old vulnerabilities in Dasan GPON home routers. DASAN Zhone Solutions is a provider of  network access solutions for service provider and enterprise networks. The company provides a wide array of reliable, cost-effective networking technologies—including broadband access, Ethernet switching, Passive Optical LAN and software-defined networks.
Attackers are targeting following two vulnerabilities in GPON home routers:

Authentication Bypass Vulnerability
It is possible to bypass authentication simply by appending “?images” to any URL of the device that requires authentication. For example by the /menu.html?images/ or /GponForm/diag_FORM?images/ URI. Attacker can then manage the device.(CVE-2018-10561)

Command Injection Vulnerability
Command Injection vulnerability exists in Dasan GPON home routers via the dest_host parameter in a diag_action=ping request to a GponForm/diag_Form URI.The router saves ping results in tmp directory and displays them when user visits diag.html. This can be used to inject and execute commands.(CVE-2018-10562)

Following exploit is spotted in the wild

The attacker takes advantage of the above vulnerabilities to bypass authetication by appending “?images” to the POST request. Then the attacker downloads a malicious executable by injecting “wget”  command. This is saved in the tmp directory and is executed when a user visits diag.html page.

SonicWall Capture Labs provides protection against this threat via following signatures:

• • IPS 13340:Dasan GPON Routers Command Injection
  • GAV:Mirai.H

Threat Graph

IoCs:
59.99.45.126
117.213.46.186
117.194.165.174
112.27.124.174
42.234.109.14
2e4506802aedea2e6d53910dfb296323be6620ac08c4b799a879eace5923a7b6

A quick look at Shodan reveals thousands of vulnerable devices

Security News

The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.