using centos7 and denyhosts 2.9 i noticed some strange behavior.
My config is set to:
DENY_THRESHOLD_INVALID = 3
DENY_THRESHOLD_VALID = 10
Which, in my understanding is like: after 3 failed login attempts of NON-EXISTING users from hosts X, deny that host.
After 10 failed logins attempts from EXISTING users from hosts X, deny that host.
While the latter works just fine, the DENY_THRESHOLD_INVALID = 3 setting does not work.
What i noticed is that the /var/log/secure, that danyhosts parses, does handly logns from non-existing accounts and logins from account that exist but are using the wrong pasword, are handled differently.
Aug 10 12:32:42 ftp sshd[27176]: Invalid user adminx from xxx.128.30.135 port 42800
Aug 10 12:32:42 ftp sshd[27176]: input_userauth_request: invalid user adminx [preauth]
Aug 10 12:32:42 ftp sshd[27176]: Connection closed by xxx.128.30.135 port 42800 [preauth]
vs.
Aug 10 12:33:46 ftp sshd[27238]: Failed password for exchange from xxx.128.30.135 port 42802 ssh2
Does anyone know of denyhosts has problems parsing the /var/log/secure file on centos with non-existing accounts vs. existing accounts that use wrong passwords?
Denyhosts debug log also does not say anything. It seems to ignore the login attempt from non-existend users.
any help would be appreciated. Thanks.
Our automated script connects to third party server (using proxy), to get some files over sftp.
It usually works fine. On a random day, I got below error. What could be the root cause.?
sftp> mget TR_ACK*.txt
Bad packet length 1131376238.
ssh_dispatch_run_fatal: Connection to UNKNOWN port 65535: Connection corrupted
Connection closed
Edit: FYI- Our script runs every 5min. The above issue occured at 12:05 min. The run at 12:00 min was also failed as the server was down at 12:00. The server was just up just before the time was 12:05 minutes.
I have ssh to a server machine and I want to run an application as a root user. I'm getting the below error,
X11 connection rejected because of wrong authentication.
X11 connection rejected because of wrong authentication.
X11 connection rejected because of wrong authentication.
Unable to init server: Could not connect: Connection refused
(eog:5473): Gtk-WARNING **: cannot open display: localhost:10.0
Note:
If I ran an application as a normal user I'm could see the GUI. The server running on Debian based distro.
I am new here.
Few days ago, attended MS azure events, and today registered with Azure (free account).
VM Environment: VM = CentOS 7, apache+php+mysql+vsftpd+phpMyAdmin
everything is up and running, able to visit the "info.php" via its public IP address.
SeLinux = disabled, Firewalld disabled.
my problem is not able to connect this server via Filezilla (PC client).
from Windows command prompt (FTP/put) is working, able to upload files.
But via Filezilla
Status: Connecting to 5x.1xx.1xx.7x:21...
Status: Connection established, waiting for welcome message...
Status: Insecure server, it does not support FTP over TLS.
Status: Logged in
Status: Retrieving directory listing...
Command: PWD
Response: 257 "/home/ftpuser"
Command: TYPE I
Response: 200 Switching to Binary mode.
Command: PORT 192,168,1,183,234,99
Response: 200 PORT command successful. Consider using PASV.
Command: LIST
Error: Connection timed out after 20 seconds of inactivity
Error: Failed to retrieve directory listing
Status: Disconnected from server
Status: Connecting to 5x.1xx.1xx.7x:21...
Status: Connection established, waiting for welcome message...
Status: Insecure server, it does not support FTP over TLS.
Status: Logged in
Status: Retrieving directory listing...
Command: PWD
Response: 257 "/home/ftpuser"
Command: TYPE I
Response: 200 Switching to Binary mode.
Command: PORT 192,168,1,183,234,137
Response: 200 PORT command successful. Consider using PASV.
Command: LIST
Error: Connection timed out after 20 seconds of inactivity
Error: Failed to retrieve directory listing
I believe that is because of the Network Security group settings for inbound and outbound rules, need open some port, but not sure, because I tried open 1024-65535 all allow, still not working.
If you use passive mode FTP, you should open ports 20,21 and ports that you need on Azure NSG(Inbound rules). You could check /etc/vsftpd.conf
pasv_enable=YES
pasv_min_port=60001
pasv_max_port=60005
For this example, you should open ports 60001-60005 on Azure NSG(Inbound rules).
This time I have another question. This one is related to FTP. We have an ftp server say 127.0.0.2. The application server is on ip say 127.0.0.1. From the application server, we connect to the FTP server every 10 minutes and pull or push certain files in the INWARD and OUTWARD folders respectively.
The ftp server is running linux with the following details:
-bash-3.2$ uname -n
ftpserver.companyname.com
-bash-3.2$ uname
Linux
-bash-3.2$ uname -r
2.6.18-308.13.1.el5
The problem is that the FTP user gets locked automatically on a random basis. Random meaning really random... This instance it is working but within the next 15 seconds it will get locked triggering of an alert and thus requiring user intervention to get it unlocked.
To check when the locking is happening, we wrote a monitoring shell script to check the ftp connection every 15 seconds. This script will only connect to the ftp machine and quit. If everything is ok, it will not do anything but if connection fails it will mail the stake holders with the ftp log.
SCRIPT >>
ftp -niv $FTP_HOST <<END_SCRIPT > $FTP_LOG
quote USER $FTP_USER
quote PASS $FTP_PASSWD
quit
END_SCRIPT
Now if we see the log generated from the script, we can see the below information:
LOG >>
::::: DATE/TIME = Wed Apr 23 17:35:00 UTC 2014 :::::
Step 1 complete : Initialised log file ~/ftp_support_23_Apr_2014.log
Step 2 complete : Completed check for ftp login
FTP connection to 127.0.0.2 is ok.
Step 3 completed. Deleted ftp.log
::::: DATE/TIME = Wed Apr 23 17:35:15 UTC 2014 :::::
Step 1 complete : Initialised log file ~/ftp_support_23_Apr_2014.log
Step 2 complete : Completed check for ftp login
FTP user username is locked on 127.0.0.2.
Step 3 completed. Deleted ftp.log
----- SAME OUTPUT AS ABOVE EVERY 15 SECONDS TILL USER IS UNLOCKED ------
Here the ftp user was unlocked by the SA.
::::: DATE/TIME = Wed Apr 23 17:41:40 UTC 2014 :::::
Step 1 complete : Initialised log file ~/ftp_support_23_Apr_2014.log
Step 2 complete : Completed check for ftp login
FTP connection to 127.0.0.2 is ok.
Step 3 completed. Deleted ftp.log
Now the question that we all have is what could have happened in 15 seconds causing the user to get locked? At 17:35:00 UTC the connection is ok, at 17:35:15 UTC, the connection goes dead. The log which is mailed to the stake holders is as below -
MAILED FTP LOG >>
Connected to 127.0.0.2.
220 (vsFTPd 2.0.5)
530 Please login with USER and PASS.
530 Please login with USER and PASS.
331 Please specify the password.
530 Login incorrect.
221 Goodbye.
Now we know for sure, that the password is read from a encrypted config file and used by the program. If it works every 10 mins, then there is no problem with the program sending the password to the ftp user. And any system user is not typing in the password incorrectly. Hence the question here is what do we need to check at our end?
How do we interpret the 530 Login incorrect. error message? Can anyone suggest what we have to do here? Has the SA changed any setting on the ftp server? What can we ask them to check at OS level or for the ftp service?
If the output of any command is needed or if any running service needs to be checked, let me know.