File and Dir permissions

Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers File and Dir permissions
# 1  
Old 04-14-2002
File and Dir permissions

I would like to configure my SuSE 7.0 workstation more securely. I have attempted for about two weeks to find a guideline on good practices for the file and directory permissions.........but to no avail.

Does anyone have a guideline that I could use to help me out. I realize that the distros are each a little different....but any help at all would be most generously appreciated.

Thanks. Smilie
# 2  
Old 04-15-2002
Re: File and Dir permissions

Originally posted by thomas.jones
I would like to configure my SuSE 7.0 workstation more securely. I have attempted for about two weeks to find a guideline on good practices for the file and directory permissions.........but to no avail.

I am not sure that such guidelines exist. Other than what are specified already by the UNIX standard for the version of UNIX that you are using. I think your real question is about security. Correct?

What are you trying to accomplish with this? UNIX is by definition fairly secure, but only depending on the honesty of the users on your box.

If you are attempting to "lock down" your box, that will be very hard to do. Permissions must remain the way they are as defaulted during the install process. If you try to lock down the box too much, your OS will have problems or your users will not be able do work on the box.

Give a few examples of what you are trying to do.

# 3  
Old 04-15-2002
For example.......i know that i need to allow access to alot of the /etc directory; using the mode 644 (-rw-r--r--) permissions.

/var/log should also be mode 644.

Reduce the amount of setuid and setgid files as much as possible.

nosuid option for /etc/fstab.

This is really what i am looking for.....just general guidelines. Problem is that, I do not fully understand the procedures and processes of the kernel and modules.

I'm just wanting to have somewhere to start. Does that explain my intentions?
# 4  
Old 04-15-2002
Un sure if this page could help your problem. But its worth a try. CHeck it out.
# 5  
Old 04-16-2002
I am not sure what your ultimate goal is. Why are you so concerned with permissions?

You are playing with fire if you change too many permissions. /etc is a VERY important directory. I know this because I had some sabotage in one of my boxes. /etc was messed up bad. Someone had changed all my files and subdirs to 444 permissions. My system almost shutdown.

Most of the daemons that run are linked to /etc. Many configuration files are located here. I would say that /etc is the most important filesystem after the box is up and running.

Please let us know what your thinking is and what has spurred you to take up this quest for modifying file permissions.

I think you are chasing your tail, just a little bit.

Don't take this the wrong way. Only as a word of caution.

# 6  
Old 04-16-2002
The permissions you set on /etc and /var are normally done because of Sendmail - it will complain if those are group writable. Changing to what you did will not effect your system.

As far as locking down a server - try this one
# 7  
Old 04-17-2002
Lexx, that is very inappropriate to say.
While OpenBSD is "secure by default", you will find yourself installing lots of stuff from the ports packages (and from other places) if you want a functioning home system. I use both OpenBSD and Linux, and have not had a problem with either, because I took the stance that the OP did. You cannot rely on the OS for all security; as there is not a whole lot of chance of somebody exploiting a flaw in the kernel itself remotely (although it may very well be possible, look at all the hooplah with zlib in the Linux kernel recently). The thing you have to worry about are the applications it runs. In the case of OpenBSD, two new exploits have been announced for it. One of them, released 4/11, is a local root exploit. I'm sure you have recompiled /usr/bin/mail with the appropriate patch (released 4/8 - 3 days before the public release of the hole) applied, right?

thomas.jones, do you have any other people who log in to the box besides yourself? If not, your worries are somewhat mitigated. The key point is to not offer any exploitable services (a key point to OpenBSD's security model). Under most circumstances, you do not need any ports listening. On my home Redhat box, I do not have any. If I ever do run X, I run it with --nolisten, to keep port 6000 closed. I don't even start inetd or xinetd, not do I provide any other services. On top of that, I can always activate my firewall rules to control any services I may open temporarily.

Let me know what you're using the machine for, and perhaps I can help with recomendations or links to recomendations.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Help- writing to dir with no write permissions (script)

hello, I have a question regarding the below script.. I just simply trying to write to a file in directory that does not have write permissions but this is failing .. it still writes to it regardless .. Many thanks in advance.. #!/bin/bash #check if dir exists, if so write to it ... (5 Replies)
Discussion started by: Reb0rn
5 Replies

2. Shell Programming and Scripting

Create file Dir and Sub Dir same time

Hi Guys , I want create files Dire and Sub Dire. as same time using variable. EX: x1="/hk/Pt/put/NC/R1.txt" x2="/hk/pt/Put/Ot/NC/RN.txt" And i want delete all after done with my script. Thanks (2 Replies)
Discussion started by: pareshkp
2 Replies

3. Shell Programming and Scripting

Have files take on DIR permissions

Hello all; I have a question based on a ticket I have from a user... K...first some background...this client needed a generic user setup to allow them to ftp files; user is called "msifpt" here's what they want to do now with this account: 1. Client will use the user id ‘msiftp'... (1 Reply)
Discussion started by: gvolpini
1 Replies

4. UNIX for Dummies Questions & Answers

How to list all files in dir and sub-dir's recursively along with file size?

I am very new to unix as well as shell scripting. I have to write a script for the following requirement. In have to list all the files in directory and its sub directories along with file path and size of the file Please help me in this regard and many thanks in advance. (3 Replies)
Discussion started by: nmakkena
3 Replies

5. Shell Programming and Scripting

Dir permissions

Hi All, I have a script which will be run by another user say user 2 which will create a new dir say dir 4 in my work place and copy certains files from his dir. /t1/t2/t3/dir4 I want to allow the user to create the dir dir4 and copy the files,but bring the control back to my name say user... (2 Replies)
Discussion started by: prasperl
2 Replies

6. UNIX for Dummies Questions & Answers

Creating a File system with required permissions for all DIR's created in

Hello All, I am application admin. I need to clear all the temporary files cleared by the applications. I need help/suggestion that is there any way to create a file system such that every Dir created in by any user will have 775 permissions. So, that i can simply clear the temporary file which... (6 Replies)
Discussion started by: firestar
6 Replies

7. UNIX for Dummies Questions & Answers

Copying dir (and sub dir) file names from ftp server to txt file in diff server

Hey all, i want to copy only the file names from an ftp server (directory and all sub directory) to a text file in another server (non ftp), i.e. i want to recursively move through directories and copy only the names to a text file. any help is appreciated...thank you in advance (1 Reply)
Discussion started by: deking
1 Replies

8. Shell Programming and Scripting

Moving file(s) from dir to dir

Hi, I am fairly new to writing scripts. I am trying to write a script that moves either One or All of the files from one directory to another. I know how to make the actual command to do it, but i don't quite know how to add operators to it, ie -i or -a. I want -i to move one file from... (4 Replies)
Discussion started by: SirJoeh
4 Replies

9. Shell Programming and Scripting

Shell Script to save/restore files and dir permissions

Hello all: I need found script to save and restore file permissions and owner:group... this is for backup my server... I have one problem in my server and file permissions and owner:group, mess up.. For this reason i need found one way to secure this aspect of the server... Thanks! (1 Reply)
Discussion started by: joangopan
1 Replies

10. Shell Programming and Scripting

copying a file from one dir to another dir

hi i have a script compareFiles() { find /tmp/Satya -type f | \ while read filename1 do echo "----------------------------------------$filename1" find /tmp/Satya -type f | \ while read filename2 do if diff $filename1 $filename2 then echo "Both files... (3 Replies)
Discussion started by: Satyak
3 Replies
Login or Register to Ask a Question