vBulletin is a commercial Internet forum software package, boasting tens of thousands of users which are growing rapidly worldwide. It is written in the PHP web language and uses the MySQL database. Owing to its large user base, vBulletin is frequently reported to have vulnerabilities. In NSFOCUS Vulnerability Database (NSVD), there are 49 entries related to vBulletin, most of which are SQL injection vulnerabilities. The vulnerability disclosed this time is of a relatively high risk level, known as remote code execution (RCE). Theoretically, an attacker can exploit this vulnerability to execute arbitrary code or even take complete control of a forum that uses this program.