David Latham

I have to reblog this article in it's full just in case the original author removes it. Here is the original. http://bashscript.blogspot.com/2010/03/unixlinux-advanced-file-permissions.html Here in plain text to ** FORCE ** it into my rubbish layout. UNIX/Linux Advanced File Permissions - SUID,SGID and Sticky Bit After you have worked for a while with Linux you discover probably that there is much more to file permissions than just the "rwx" bits. When you look around in your file system you will see "s" and "t" $ ls -ld /tmp drwxrwxrwt 29 root root 36864 Mar 21 19:49 /tmp $ which passwd /usr/bin/passwd $ ls -l /usr/bin/passwd -rwsr-xr-x 1 root root 22984 Jan 6 2007 /usr/bin/passwd What is this "s" and "t" bit? The vector of permission bits is really 4 * 3 bits long. Yes there are 12 permission bits,not just 9.The first three bits are special and are frequently zero. And you almost always learn about the trailing 9 bits fir...

I would like to share this post on Linux Security. I would place it in my shared items but I thought that if I left it there it would go largely unnoticed. The author has written a fantastic entry about the User effect on security within a Linux environment. He makes points about users running arbitrary code as root, installing unsigned packages and a lot more. It is well worth a read! http://www.happyassassin.net/2009/01/20/on-linux-security/ I would like to note that I am merely trying to introduce a great piece of writing by another blogger.