Nexxt Solutions Nebula 300+ vulnerabilities

Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which contains Base64-encoded credential data combined with a static suffix. Because the encoding is reversible and lacks integrity protection, an attacker can reconstruct or forge a valid cookie value without proper authentication.

Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware up to version 12.01.01.37 allows remote enablement of a Telnet service. An authenticated attacker can send a crafted POST request with parameters such as telnetManageEn=true and telnetPwd to activate Telnet on port 23.

Missing authentication in the /goform/ate endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows an adjacent unauthenticated attacker to retrieve sensitive device information, including the administrator password. An attacker can decode this value to obtain valid administrative credentials and authenticate to the device.