To enable exec() function, you have to modify php settings using a php.ini file.
- Open php.ini file and search for disable_functions exec
- Delete “exec” from disable_functions
disable_functions = "show_source,system, shell_exec,exec"
- Save the changes and reboot server.
When a PHP script is hacked, the hacker can use the exec function to cause further issues. However, exec function itself is not dangerous.
OJS needs exec function for extracting text from PDFs for search indexing etc.