No, not unless the privileges on the file have been set wrong, or someone made an editor or something setruid root or gained root (or group shadow) on your system.
The Shadow Suite solves the problem by relocating the passwords to
another file (usually /etc/shadow). The /etc/shadow file is set so
that it cannot be read by just anyone. Only root will be able to read
and write to the /etc/shadow file. Some programs (like xlock) don't
need to be able to change passwords, they only need to be able to
verify them. These programs can either be run suid root or you can
set up a group shadow that is allowed read only access to the
/etc/shadow file. Then the program can be run sgid shadow.
-rw-r----- 1 root shadow 493 2007-08-19 08:36 /etc/shadow
See 'man shadow' and the stuff in /usr/doc/shadow-(version)/.