Rehashing My File Permissions Understanding(or lack of it)

[Paul Howarth]

Jay Paulson wrote:
> I was under the impression that changing the umask was a possible 
> security risk.  Am I correct in thinking that?

Possibly, possibly not. Using a umask of 002 instead of 022 is something 
that Red Hat/Fedora specifically cater for. What this means is that woth 
a umask of 002, files are created with group write permissions by 
default, so if your default group is shared with a number of other 
people then they will be able to write to your files by default. 
However, in Red Hat/Fedora, every new user is created with their own 
group by default, which isn't shared with any other user. So enabling 
group write permission isn't a big issue. What this then lets you do is 
to create a separate group for shared data, and then everyone's default 
umask being 002 (if set that way) then makes it easy for all members to 
create and edit files with this shared groupid.

Paul.