In modules/HELPBOT_MODULE in Budabot 0.6 through 4.0 lax syntax validation allows remote attackers to perform a command injection attack against the PHP daemon with a crafted command resulting in a denial of service or possibly unspecified other impact as demonstrated by the \!calc 5 x 5\ command. In versions before 3.0 modules/HELPBOT_MODULE/calc.php has the vulnerable code; in 3.0 and above modules/HELPBOT_MODULE/HelpbotController.class.php has the vulnerable code.