Cacti: Command Injection via escape_command() no-op in RRDtool execution

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior are vulnerable to Command Injection due to lack of sanitization in the escape_command() function. The escape_command() function at lib/rrd.php is a no-op: it returns $command unchanged. The command line built by rrdtool_function_graph() is passed through this function and then to shell_exec($full_commandline). The risk is in __rrd_execute() where text_format values from graph templates (which may contain host variable substitutions) reach shell_exec without adequate escaping. This issue has been addressed in version 1.2.31.