Cayin CMS suffers from an authenticated OS semi-blind command injection vulnerability using default credentials. This can be exploited to inject and execute arbitrary shell commands as the root user through the 'NTP_Server_IP' HTTP POST parameter in system.cgi page. This issue affects several branches and versions of the CMS application including CME-SE CMS-60 CMS-40 CMS-20 and CMS version 8.2 8.0 and 7.5.