I have got some issues in running a PHP file that needs to do shell_exec, fopen and fwrite things. so after trying to change the permissions the script is working fine now .
Now I am having this type of permissions for www folder

drwxrwx— 16 root www-data 4096 Nov 29 01:41 www

and within www folder all folder are having the following permissions
drwxrwx— 3 root www-data 4096 Nov 27 23:41 foldername

all files within the /var/www/ are having the following permissions
-rwxrwx— 1 root www-data 13 Nov 27 13:09 index.html

Is that recommended and secured to have these permissions ?
all files, even the non executable files are in green color .

if its not secured, then what kind of permissions should I have to apply ?

thanks in advance !