The Billion 5200W-T TCLinux Fw $7.3.8.0 v008 130603 router distributed by TrueOnline has three user accounts with default passwords, including two hardcoded service accounts: one with the username true and password true, and another with the username user3 and and a long password consisting of a repetition of the string 0123456789. These accounts can be used to login to the web interface, exploit authenticated command injections, and change router settings for malicious purposes.
Use CWE-798, Billion vendor hub and 5200w-T Firmware product page to widen CVE-2017-18373 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2017-18368, CVE-2017-18371 and CVE-2017-18369 for nearby disclosures in the same product family.