Yes, and no.
Anyone who has access through a shell or runs an application with his/her credentials can read/write/execute the file with 777 permissions, regardless of the security group they are in.
However, if you are talking about a web-accessible application, it is not the actual *user* accessing the file, but the HTTP process instead. with apache, that's normally the 'nobody' user, which is a limited access account for security purposes.
Apache normally validates credentials on its own, and can choose to make modifications to a file on the users behalf if it agrees that everything checks out -- but the user wouldn't be able to drag/drop a file over or something, you'll need some kind of process that will accept the upload, validate the user, and save the data.
One way of doing that is through FTP, another is PHP/CGI/Perl through a webserver.
Anyone who has access through a shell or runs an application with his/her credentials can read/write/execute the file with 777 permissions, regardless of the security group they are in.
However, if you are talking about a web-accessible application, it is not the actual *user* accessing the file, but the HTTP process instead. with apache, that's normally the 'nobody' user, which is a limited access account for security purposes.
Apache normally validates credentials on its own, and can choose to make modifications to a file on the users behalf if it agrees that everything checks out -- but the user wouldn't be able to drag/drop a file over or something, you'll need some kind of process that will accept the upload, validate the user, and save the data.
One way of doing that is through FTP, another is PHP/CGI/Perl through a webserver.