playSMS before 1.4.5 allows Arbitrary Code Execution by entering PHP code at the #tabs-information-page of core_main_config, and then executing that code via the index.php?app=main&inc=core_welcome URI.
import.php (aka the Phonebook import feature) in PlaySMS 1.4 allows remote code execution via vectors involving the User-Agent HTTP header and PHP code in the name of a file.
PlaySMS 1.4 allows remote code execution because PHP code in the name of an uploaded .php file is executed. sendfromfile.php has a combination of Unrestricted File Upload and Code Injection.