Security of SHARE_MEM_FILE

[Lee Adamson]

I am using Samba 1.9.17p2 with FAST_SHARE_MODES (Solaris 2.5).
The default permissions on the SHARE_MEM_FILE are 0666. Does
anybody know why this is and what the implications would be
if a user corrupted this file?

I noticed in the source that there is a possibility to
#define SECURE_SHARE_MODES (line 394 shmem.c) to change the
permissions to 0600. Why is this not be the default?
I presume something will break if I set it!