3
votes
3answers
60 views

Monitor all login attempts

Few weeks ago I thought it would be a good idea to write a script to send me an email whenever some user logs in into my server. So I came with a perfectly working script notifyLogin.sh, then I ...
5
votes
1answer
132 views

gdm greeter configuration: Exclude all *except* for one specific user

I have Googled this one and tried so many combinations, with no success. I need the GDM login greeter to display one and only one username. In effect, what I need is something like this in ...
8
votes
3answers
177 views

Trap: can't su as root, can't change group to wheel, ssh as root prohibited

Is this a trap? I made these steps in FreeBSD 10: 1) ssh as root prohibited 2) logged as user 3) su as root 4) as root chsh changed name of user "user" to "luser" 5) exit from ...
4
votes
1answer
473 views

Using LDAP for authentication, how can I safely disable/deactivate an account without deleting it?

We use LDAP for authentication for thousands of users. The primary tactic we have been employing to make a user unable to login, without removing their account, is to change the LDAP attribute ...
2
votes
1answer
161 views

Was my Unix server compromised?

Someone asked if this constituted a break-in and wondered if their server had been compromised. Jan 12 04:16:51 foo sshd[26725]: Failed password for root from 61.174.51.207 port 1076 ssh2 Jan 12 ...
3
votes
1answer
166 views

present users a login prompt? /bin/login? getty?

I have a service that execs a command when a user connects to it through a socket, and redirects everything it receives to the executed program. It works ok with shells like bash, giving the user a ...
2
votes
1answer
446 views

AIX 6.1 — Without root can I get the last failed login for a user i have access to?

I know the information is in the security files but I don't have access and it's more work then I want to do to go to our Unix admins to get the information (everytime the account gets locked which is ...
4
votes
2answers
3k views

How to find out out WHEN an user account was locked

With passwd -S user_name one can find out, if an account is locked, but is there a way to find out when it was locked and who it locked? Further links: http://serverfault.com/a/485760/78439 Disable ...
1
vote
1answer
762 views

Is there a way to report incorrect login attempts in Ubuntu 12.10?

I am concerned with some people trying to access my laptop while I am away in my work place. Therefore I was wondering if is there a way to set up kind of automatically monitor and report wrong ...
3
votes
2answers
301 views

why slight delay after failed login in tty [duplicate]

Possible Duplicate: Why a wrong password gives a big delay Whenever I mistype my password when logging in in a tty, I have noticed that I have to wait for a second before I'm able to log in ...
5
votes
1answer
159 views

OpenBSD and limiting login to local only like in FreeBSD's login.access(5)

I am using OpenBSD as my desktop. I don't want to login to my machine remotely, and I don't want anyone else to login remotely. In FreeBSD there is a file called login.access(5) that can be used to ...
6
votes
2answers
11k views

Effect of entries in /etc/securetty

By default on RHEL 5.5 I have [deuberger@saleen trunk]$ sudo cat /etc/securetty console vc/1 vc/2 vc/3 vc/4 vc/5 vc/6 vc/7 vc/8 vc/9 vc/10 vc/11 tty1 tty2 tty3 tty4 tty5 tty6 tty7 tty8 tty9 tty10 ...
9
votes
4answers
29k views

SSH login with clear text password as a parameter?

I need to login to a user that I've created on a remote host running Ubuntu. I can't use an ssh key because the ssh login will happen from a bash script ran within a server that I wont have access to ...
6
votes
8answers
11k views

Is it possible to test user name and password?

I've written a python CGI script that invoke bash commands, and it needs to test for a successful login on the host. Is it possible to create a bash script that will test a given username and ...
35
votes
7answers
26k views

What's the difference between /sbin/nologin and /bin/false

Technically, unless pam is set up to check your shell with pam_shells neither of these can actually prevent your login, if you're not on the shell. On my system they are even different sizes, so I ...
3
votes
1answer
3k views

Can a user with /sbin/nologin shell login through ssh?

Is it possible to ssh to a machine as a user with no valid shell (say, mail)? So far I cannot, and using the command below doesn't work: $ ssh mail@machine.local /bin/bash It will always say "This ...
5
votes
2answers
696 views

make a 2nd root?

I was thinking, maybe i'd like to disable passwords for the root user and only use keys to log in. and if i need to login without keys have a 2nd user that is like root in everyway except has a ...
82
votes
7answers
11k views

Which is the safest way to get root privileges: sudo, su or login?

I would like to have the root account in safety even if my unprivileged user is compromised. On Ubuntu you can only use sudo for "security reasons" by default. However I am not sure it is any safer ...
12
votes
11answers
1k views

Concern about logging in as root overrated?

For personal linux on my personal notebooks, I've usually set my environment to autologin as root even under X or lower runlevels. I've found my workflow is very pleasant and fast, without any ...