Protecting against CVE-2018-14634 (Mutagen Astronomy)

There is a new exploit, rated as 7.8 severity level,  that affects major Linux distributions of RedHat Enterprise Linux, Debian 8 and CentOS named Mutagen Astronomy. Mutagen Astronomy exploits an integer overflow vulnerability in the Linux kernel and supplies root access (admin privileges) to unauthorized users on the intended server. This exploit affects Linux kernel version dating back from July 2007 to July 2017.  Living in the Kernel, the memory table can be manipulated to overflow using the create_tables_elf() function. After overwhelming the server, the hacker can then overtake the server with its malicious intents.

As mentioned this vulnerability is present in RedHat, Debian 8, and CentOS distributions but is limited to affecting only 64-bit versions as the 32-bit versions do not have the address space to overwhelm the server.  Along with 64-bit versions, the exploit is also limited to Linux Kernel versions 2.6.x, 3.10.x, and 4.14.x. (Read our article How To Check the Kernel Version to see which version you are running)  Proof of concept reported on August 31, 2018, and although remediation from a one-year-old patch was backported to most LTS (long-term support) kernels, CentOS and Debian 8 remain vulnerable.

RedHat has recently released a patch and updating to kernel-3.10.0-862.14.4.el7.x86_64.rpm will keep you safe from Mutagen Astronomy. Unfortunately, CentOS and Debian 8 distributions have not yet released a patch for the Mutagen Astronomy vulnerability but stay tuned as we will be updating this article once information is released.

 

How to Install and Configure vsftpd on CentOS 7

FTP (File Transfer Protocol) is one of the most popular methods to upload files to a server. There exist a wide array of FTP servers, such as vsftpd, you can use and FTP clients exist for every platform.

Essentially no matter what OS you use you can find an easy to use FTP client, so it makes for a great solution to transfer files. On CentOS based servers before you can connect via FTP you’ll have to setup an FTP server. Here we’re gonna setup vsftpd which is a great option since it has a focus on security and speed.

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How to enable EPEL repository?

The EPEL repository is an additional package repository that provides easy access to install packages for commonly used software. This repo was created because Fedora contributors wanted to use Fedora packages they maintain on RHEL and other compatible distributions.

To put it simply the goal of this repo was to provide greater ease of access to software on Enterprise Linux compatible distributions.

What’s an ‘EPEL repository’?

The EPEL repository is managed by the EPEL group, which is a Special Interest Group within the Fedora Project. The ‘EPEL’ part is an abbreviation that stands for Extra Packages for Enterprise Linux. The EPEL group creates, maintains and manages a high quality set of additional packages. These packages may be software not included in the core repository, or sometimes updates which haven’t been provided yet.
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Change a Password for PostgreSQL on Linux via Command Line

PostgreSQL supports many client authentication methods, but in this case we’re only going to concern ourselves with two: password and md5.

Note: The default authentication method for PostgreSQL is ident. If you’d like to change the PostgreSQL authentication method from ident to md5, then visit the linked tutorial!

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Change PostgreSQL Authentication Method from Ident to MD5

PostgreSQL supports multiple client authentication methods including: trust, reject, md5, password, gss, sspi, krb5, ident, peer, ldap, radius, cert, and pam. Here we’re only going to concern ourselves with two: ident and md5.

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What is the Default Password for PostgreSQL?

When connecting to PostgreSQL on Linux for the first time many admins have questions, especially if those admins are from the MySQL world.

By default, when PostgreSQL is installed, a postgres user is also added.

If you run the command:

cat /etc/passwd

… you’ll see the postgres user.

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How to Upgrade and Patch cPanel / WHM

Pre-Flight Check

  • These instructions are intended specifically for checking your version of cPanel or WHM via the command line or the WHM dashboard.
  • I’ll be working from a Liquid Web Managed CentOS 7 server, and I’ll be logged in as root.

Step #1: Log In to WHM

First, log in to WHM. You’ll arrive at your WHM dashboard:

How to Upgrade and Patch cPanel WHM

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Error: Login without a password is forbidden by configuration (see AllowNoPassword) [SOLVED]

This error relates to logging into phpMyAdmin, an open source tool used for the administration of MySQL.

Once in awhile, perhaps on a Development server, MySQL won’t be setup with a root password. The aforementioned configuration is generally thought of as against best practices however, if it is what you’re dealing with, then it could also interfere with phpMyAdmin.

Pre-Flight Check

  • These instructions are intended specifically for solving the error: Login without a password is forbidden by configuration (see AllowNoPassword).
  • I’ll be working from a Liquid Web Self Managed Ubuntu 15.04 server, and I’ll be logged in as root.

The Error

The error will read “Login without a password is forbidden by configuration (see AllowNoPassword)” as shown below.

Error Login without a password is forbidden by configuration (see AllowNoPassword) [SOLVED]
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Find (View) Default Zone for Firewalld on CentOS 7

Pre-Flight Check

  • These instructions are intended for finding (viewing) the default zone in Firewalld on CentOS 7 via the command line.
  • I’ll be working from a Liquid Web Core Managed CentOS 7 server, and I’ll be logged in as root.

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Find (View) Active Zones in Firewalld on CentOS 7

Pre-Flight Check

  • These instructions are intended for finding (viewing) active zones in Firewalld on CentOS 7 via the command line.
  • I’ll be working from a Liquid Web Core Managed CentOS 7 server, and I’ll be logged in as root.

Continue reading “Find (View) Active Zones in Firewalld on CentOS 7”