Archive for Linux

Two Factor SSH Authentication with Duo Security

As is probably obvious from our blog posts on Yubikey SSH/WordPress two factor authentication and Google Authenticator SSH two factor authentication, we at MNX Solutions are big proponents of multi-factor authentication schemes to add security to infrastructure. On the other side of things, though, we have to be agile system administrators in order to offer […]

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Automatically purge old configuration from Nagios deployed by Puppet

A problem that Puppet administrators have likely noticed when deploying its built-in Nagios functionality (called Naginator) is that creating configuration is very easy but ‘cleaning’ old configuration isn’t as straight-forward. If you are like me, you’d delete the affected file(s) that had cruft and let Puppet re-build the service configuration without the old services or […]

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Amazon EC2 instance not starting

While working on a failed EC2 (ebs backed) instance recently, we were presented with an instance that would not start after reboot or stop/start. tl;dr: Create a snapshot of the existing EBS vol; remount and edit etc/fstab; re-attach and start the instance.

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ProFTPD Remote Code Execution Vulnerability and exploit

A flaw in the popular ProFTPD FTP server potentially allows unauthenticated attackers to compromise a server. The problem is caused by a buffer overflow in the pr_netio_telnet_gets() function for evaluating TELNET IAC sequences. ProFTPD bug report: http://bugs.proftpd.org/show_bug.cgi?id=3521 All MNX Solutions Linux Server Management customers have been patched.

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Server Management Best Practices – Firewall

Every week at MNX solutions we handle issues from server security and patch management to system recovery and performance tuning. In this blog series, we will review a number of firewall best practices that you can implement today on your server infrastructure. First things first, do you utilize a firewall on your server? If your […]

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bash_history date

Bash_history date Ever try to determine what caused the latest outage by trying to determined when a command was last executed? Look in your .bash_history (if you are running a bash shell), and you will see your recently executed commands. However, it is generally impossible to tell when the command was executed.

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yum python logger error bad marshal data

Interesting bug encountered today after a fresh install of RHEL5 from 5.3 media. When attempting to run the command, ‘yum’.  The following error was presented: # yum Traceback (most recent call last): File “/usr/bin/yum”, line 4, in ? import yum File “/usr/lib/python2.4/site-packages/yum/__init__.py”, line 30, in ? import logging ValueError: bad marshal data

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CentOS5 and PHP52 upgrade rpms

We encounter many scenarios where using the latest version of PHP is required. No great way, aside from downloading the PHP5 source and compiling, is available. That is, until you discover then IUS Community Project.

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Upgrade Urchin5 from RHEL3 to RHEL5

Just a quick note about upgrading the operating system, or migrating your Urchin 5 installation from RedHat 3 -> RedHat 5 (or CentOS5). You think you’ve done everything properly, and you probably did.  But you are getting some DNS resolution error messages like:

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Installing IonCube in cPanel

To install IonCube loading in cPanel, run the following as root: # /scripts/phpextensionmgr install IonCubeLoader You can then check if ionCube was installed by running: # php -v

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