CVE-2022-30325

Vulnerability

The TRENDnet TEW-831DR router (firmware version 1.0 601.130.1.1356) uses a default pre-shared key (PSK) for both 2.4 GHz and 5 GHz Wi-Fi networks that is identical across all devices except for the last four digits [1]. This means the PSK is highly predictable, as only a small portion varies per device.

Exploitation

An attacker within wireless range of the router can attempt to guess or brute-force the last four digits of the default PSK. Since the first portion is known (the same for all devices), the effective keyspace is reduced to 10,000 possibilities (0000-9999) or less if the digits are not random. No authentication or prior access is required; the attacker only needs to be within Wi-Fi range.

Impact

Successful exploitation allows the attacker to connect to the victim's Wi-Fi network. Once connected, the attacker may be able to intercept network traffic, perform man-in-the-middle attacks, or access other devices on the local network. The attacker gains the same level of network access as any legitimate Wi-Fi client.

Mitigation

As of the publication date (2022-06-16), no firmware update or official mitigation has been disclosed by TRENDnet for this issue [1]. Users are advised to change the default Wi-Fi pre-shared key to a strong, unique passphrase. If the router is no longer supported, replacement with a device that enforces unique default credentials is recommended.