February 2003
Intermediate to advanced
986 pages
35h 34m
English
book
Practical UNIX and Internet Security, 3rd Edition
by Simson Garfinkel, Gene Spafford, Alan Schwartz
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Chapter 6: Filesystems and Security
Learn about the useful options to your version of the ls command.
If your system has access control lists (ACLs), learn how to use them. Remember: do not depend on ACLs to protect files on NFS partitions.
Set your umask to an appropriate value (e.g., 027 or 077).
Never write SUID/SGID shell scripts.
Periodically scan your system for SUID/SGID files.
Disable SUID on disk partition mounts (local and remote) unless it is necessary.
Determine if write, chmod, chown, and chgrp operations on files clear the SUID/SGID bits on your system. Get in the habit of checking files based on this information.
Scan for device files on your system. Check their ownerships and permissions to ensure that they are reasonable.
Consider using a cryptographic filesystem for sensitive data.
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.