The flaw in the /goform/ate endpoint of Nexxt Solutions Nebula 300+ firmware is a missing authentication requirement, categorised as CWE-306. An adjacent attacker who can reach the device can submit a request to that endpoint and receive a raw response that contains configuration parameters, including the Login_PW field encoded in Base64. Decoding that payload reveals the active administrator password, giving the attacker full control of the device and the ability to modify, disable, or exfiltrate data.

The vulnerability affects Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 and devices running Tenda F3 V2.0 firmware. Any deployment of these products installed on a local network is susceptible.

With a CVSS score of 7.1 the vulnerability is classified as high severity. The EPSS score is below 1% and it is not listed in CISA’s Known Exploited Vulnerabilities catalog. The likely attack vector is a local network adversary that can reach the device; the exploit requires only network connectivity and no privileged credentials. Once the attacker accesses the endpoint, the information disclosed can be used directly to authenticate and gain administrative control.