Ubuntu Security :: SSH Login Attempts Using WINBIND ?
Oct 23, 2010
I have an SSH server on my laptop, and I'm using the default configuration file, but I added "AllowUsers <myUserName>". I get lots of login attempts like the ones below in my /var/log/auth.log.From Google, I find that pam_winbind allows some kind of Windows authentication. This leaves me with 2 questions. What does winbind do when I have not configured any Windows/Samba accounts? How can I turn it off?
Oct 23 20:01:49 muon sshd: User root from 22.214.171.124 not allowed because not listed in AllowUsers
I am running a ubuntu server 10.10 with SSH, and OpenVPN. I use it mainly for the VPN, but I have seen log in attempts such as:
Mar 22 14:52:53 UbuntuSvr sshd: Invalid user support from 126.96.36.199 Mar 22 14:52:55 UbuntuSvr sshd: Invalid user student from 188.8.131.52 Mar 22 14:52:57 UbuntuSvr sshd: Invalid user transfer from 184.108.40.206 Mar 22 14:52:59 UbuntuSvr sshd: Invalid user user from 220.127.116.11
Is it possible to make it so when some one has tried logging in 5 times with an invalid user/pass that the ip is banned for 10 minutes? I have password auth set to no and am using keys.
I know this is probably easy and if I only took a while to figure it out maybe I could but I have some stuff that needs to happen soon and I can't figure this out. I was wondering how I could have a log monitor that would email me whenever someone tries to login over ssh to my system. I'm open to everything daemons/scripts or cron itl works as I am not running a production server (but I might be starting that soon). Oh and just a side how do I get sent an email when I get port scanned
I am trying to get OpenLDAP to authenticate user logins, but running around in circles. Are there any logs produced by either client and/or server that would indicate possible reasons why it was unable to login as a user?Below is an explanation, any ideas would be appreciated, as I think everything is setup as per the various articles on using LDAP.
I have a CentOS 5.5 OpenLDAP server, and several others, some host services, some are file shares (samba).So far I have been able to successfully configure OpenLDAP to carry out all the ldap* commands from both the local server and from any of the remote servers, either via non-ssl or ssl connections. However, as soon as I try connecting any services up to it, it doesn't play ball.Back to basics, having cleared off all previous attempts at this from all machines, I have gone through the following:
Installed OpenLDAP server/client on host (plus nss_ldap). Configured /etc/openldap/slapd.conf (see below) Configured /etc/openldap/ldap.conf (see below)
How do I limit the max login attempts in the sshd_config file? I found a way to do it on Google some time back but I can't find it now. I have Denyhost already, but I really wanna do the "MAx Login Attempts" what ever it was that I was able to do in the config file.
I'm running the firestarter firewall and its been showing the odd ssh attempt quite often. e.g. I've had 4 attempts today, 3 in the last 40mins. I realize that this may be nothing to serious but it's got me curious, aside from having a secure password (which I have) is there anything that else that I can do to ensure that my system is as secure as possible from ssh? I do use ssh within my home network so I don't want to disable it completely.
Somehow an app on this box seems to have disappeared long ago which was configured to start immediatedly with a root login (eg su). Now, whenever upgrading permissions to root or logging (and assuming login as root), an error displays saying "cannot find <application>"
Considering root usually is different than other logins, am not sure where to start looking on an OpenSuSE box. I've tried without success
BASH -v to enable verbose mode before executing a "su." BASH --debugger to enable debugging mode before executing a "su."
Logout, Login as root and inspect /var/log/ hoping to find some logfile that audits the login sequence, but may be looking at a wrong logfile.
My server (CentOS 5.4) is being bombarded 24x7 with IP addresses from China trying to exploit phpMyAdmin. For every one I block on the firewall, half a dozen come to the funeral! It's a pity these morons don't have something better to occupy their time. I'm getting page after page of this (see below) every day and it's been going on for weeks. I don't even have phpMyAdmin on the server. I don't use it and I deleted it.
I've read that you can use .htaccess and / or mod_rewrite to redirect / block them based on any query for phpMyAdmin (they try all letters in upper and lower case, leading to page after page). Unfortunately, I have no idea of how to do this. I already have an .htaccess file. Maybe someone can suggest what to add to stop these pests from wasting my bandwidth and suggest somewhere I could redirect them to to cause them maximum problems. I don't want to block the entire country, seems a bit like overkill, not all Chinese are morons. we aren't even in the USA, so why they are doing this is beyond me.
A TINY sample! [Sun Aug 08 13:29:08 2010] [error] [client 18.104.22.168] File does not exist: /var/www/corp/phpMyAdmin-2.7.2
currently I'm fiddling around with mod_security for apache2 configurations on CentOS boxes, right now in a test environment first (i.e. separate non production box).CentOS includes the mod_security "Core Rule Set" by Breach Security Inc, the devs behind that module.So far all's running mostly, logs/auditlogs etc.For simple testing, I made a small php form as following:
Code: <?php $link = mysql_connect("localhost",$user,$pass); //un/pw obfuscated for forum post
On my server I some times login from my home where I have an internet connection which does not have a static IP each time I switch on my modem a dynamic IP isgenerated.I see in auth.log logs of following lines Quote:reverse mapping checking getaddrinfo forkkts-kk-dynamic-01.1.168.192.some_broadband.in [192.168.1.2] failed - POSSIBLE BREAK-IN ATTEMPT Accepted publickey for root from 192.168.1.2 port 22852 ssh2when ever I login to my server from home.In this case I do know that it was me who logged in but still why do I see such a log.What is this complaining about?
Yesterday I applied the su security patch to my openSuSE 11.2 x86_64 system.After applying the patch, any attempt at su failed, and after rebooting the system earlier this morning any login (root, user, otherwise) fails with a "Permission Denied".Is it possible that the su update somehow messed up my (standard) pam settings?
For about a week now I've been seeing mass attempts to relay through postfix and login to dovecot from the same 2 addresses, none are successful due to how postfix/dovecot are configured and I wouldn't be overly worried but my isp have picked up on it and are nagging at me
What ways do people go about just dropping connection attempts from offending addresses/ranges when stuff like that happens? An ideal thing would be something that detects repeated failed attempts from a host or range and subsequently ignore/ban them, perhaps for a specified length of time, something along the lines of denyhosts and fail2ban for ssh would be great Don't know if there's anything out there or just a plain tried and trusted method anyone might use for stuff like this, if not a hint on the most appropriate way to go about it 'manually' would do
i updated both browsers i have and lost my secure log-in pages (no padlocks showing ) concerning different Web mail accounts.Just before i did these updates i checked an unrelated thing on-line regarding my sound card of which i kept a copy of and got this message below :
!!ALSA/HDA dmesg !!------------------ [ 12.762633] cfg80211: Calling CRDA for country: AM
I'm seeing really bad user login format under a standard installation and am wondering why ubuntu does this as default. I have noticed that the graphical login for gnome sizes itself to accommodate a user's exact password length. This indicates to me that somewhere on the unencrypted part of a standard installation with user encryption contains at least some indication of the content of the password length which seems a security flaw even if not a complete hole, it majorly reduces the number of attempts a cracker would have to cycle through.
And that's assuming that *only* the length is contained. Furthermore it seems that it would be MUCH better to simply display the number of characters entered into the pw field and allowing the gui to expand itself from an fixed size as the field is filled out so the the user still receives visual feedback for entering characters. Either a simple character count display should be entered into the field or a 10 dot to new line so that one can visually quickly count the number enter by multiplying from a 10base graphical observation.
just migrated to Lucid from Jaunty and noticed that the login startup screen looks more like windoze (shows all authorized users).One of the endearing security checks with Unix was that if you had access to a console you had guess both userid AND password - the system wouldn't tell you which was wrong.I feel that we have lowered security by making the list of authorized users visible on a console. Is there any way to turn it off and force users to enter both userid and password?