Que tal:
find . -type d -exec cp file {} \;
De man find
:
-type c
File is of type c:
d directory
-exec command ;
Execute command; All following arguments to find are taken
to be arguments to the command until an argument consisting
of ';' is encountered. The string '{}' is replaced by the
current file
Portanto, o comando acima encontrará todos os diretórios e executará cp file DIR_NAME/
em cada um deles.