strange thing appens on SCO

[fabio () TELEMAIL IT (Fabio Pietrosanti)]

Playing around a SCO OpenServer i notice this thing...
If i copy a file using cp -p it preserve also ownership of the file.
How should this appens? If i'm user test how could i write a file
with bin permission ? suid cp?
look here...

#### Sco OpenServer ####

$ uname -a
SCO_SV ibis2 3.2 5.0.5 i386
$ id
uid=209(test) gid=50(group) groups=50(group)
$ cp -p /etc/passwd /tmp/test1
$ ls -al /tmp/test1
-rw-rw-r--   1 bin      auth        1208 Jan 31 15:18 /tmp/test1
$ ls -al /etc/passwd
-rw-rw-r--   1 bin      auth        1208 Jan 31 15:18 /etc/passwd
$ ls -al /bin/cp
lrwxrwxrwx   1 root     root          30 Dec 15  1999 /bin/cp ->
/opt/K/SCO/Unix/5.0.5Eb/bin/cp
$ ls -al /opt/K/SCO/Unix/5.0.5Eb/bin/cp
-rwx--x--x   1 bin      bin        35860 Jul 28  1998
/opt/K/SCO/Unix/5.0.5Eb/bin/cp
$ cp /etc/passwd /tmp/test2
$ ls -al /tmp/test2
-rw-r--r--   1 test     group       1208 Jul 20 13:16 /tmp/test2

#### Linux ####

naif:~$ uname -a
Linux naif 2.2.16 #2 Tue Jul 4 18:34:31 CEST 2000 i686 unknown
naif:~$ cp -p /etc/passwd /tmp/test1
naif:~$ ls -al /tmp/test1
-rw-r--r--   1 naif     users         420 Jul 13 15:12 /tmp/test1
naif:~$ cp /etc/passwd /tmp/test2
naif:~$ ls -al /tmp/test2
-rw-r--r--   1 naif     users         420 Jul 20 13:24 /tmp/test2
naif:~$ ls -al /bin/cp
-rwxr-xr-x   1 root     bin         27188 Jun 21 10:31 /bin/cp*

naif () itapac net

X.25 Network Never Die !!!