Tag: digitalocean

Find Shellshock Exploit Attempts & Probes From the Command Line and Papertrail

Never hurts to make sure

I’ve written about Papertrail a few times before, I love the service and it’s just too valuable to not use.

Papertrail makes it super easy to find Shellshock exploit attempts and probes. Probes are just checking a machine to see if it’s vulnerable to Shellshock. If you’re using CloudFlare, you’ll never see any Shellshock attempts show up in your logs, CloudFlare doesn’t even let them through.

See If Shellshock Affects You

Checking to see if your system is vulnerable to Shellshock is quite easy. It takes a relatively simple bash command:

env x='() { :;}; echo vulnerable to shellshock' bash -c "echo All good"

Run that code in a terminal. If you see All good, you’re not vulnerable. However, if you see vulnerable to shellshock, you are potentially vulnerable.

Yahoo-WinZip-Servers-Shellshock-Bug

Shellshocker.net provides a script that will download, compile, and install the newest version of bash for you. You should only use it though if your Linux distribution hasn’t already provided updated security release packages. If you’re interested, the code that runs Shellshocker.net is available on GitHub.

Find Shellshock Attemps and Probes Via The Command Line

This is very easy as long as you know the location of your Apache access log file. It’s typically something like /var/log/apache2/access.log. Assuming that’s the location of your Apache access log file, this command will pull out all the Shellshock probes and attempts:

grep '() {' /var/log/apache2/access.log

If nothing was returned, that means nobody has been trying to exploit Shellshock on your system, or even checking to see if your system is susceptible to Shellshock. If results are returned, look them over carefully to examine where the attempts are coming from, an IP address will be associated with every attempt.

Shellshocker.net Checker

Shellshocker.net also provides a bash script to check your machines for the Shellshock vulnerability. You can download the script and run it manually from your terminal, or, if you have cURL installed, run the following command:

curl https://shellshocker.net/shellshock_test.sh | bash

Running that command will produce results similar to the screenshot seen below. It checks for a number of Shellshock related vulnerabilities.
shellshocker

Find Shellshock Attemps and Probes With Papertrail

Go to your Papertrail events tab and search for the following:
"() {"

If anything is returned, those are Shellshock probes. Some example probes are listed in the gist that’s embedded below. None of the offending IP addresses have been redacted.

These actually made it through to Papertrail, which shouldn’t happen since longren.io sits behind Cloudflare. I’ll open a support ticket with them about it and update this post later.

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Scotch Box: A Vagrant LAMP Stack That Just Works

Just a dead-simple local Vagrant LAMP stack for developers

I discovered Scotch Box recently, brought to us by the folks at scotch.io. It actually looks like Nicholas Cerminara has done most of the work, or as least done all of the committing to GitHub. Here’s the Scotch Box announcement at the Scotch.io blog.

After using Scotch Box for a day, I’ve decided this is how I will do all future development work. It’s so easy, and you really don’t need to know much about Vagrant or VirtualBox to get up and running with Scotch Box.

Scotch Box has a repository setup at GitHub that explains how to make use of Scotch Box. Basically, just clone the repository, and then run vagrant up inside that repo.

Scotch Box is currently running Ubuntu 12.04.5. Here’s a bit from the Scotch Box readme:

Scotch Box is a preconfigured Vagrant Box with a full array of LAMP Stack features to get you up and running with Vagrant in no time.

A lot of PHP websites and applications don’t require much server configuration or overhead at first. This box should have all your needs for doing basic development so you don’t have to worry about configuring Vagrant and you can simply focus on your code.

No provisioning tools or setup is really even required with Scotch Box. Since everything is packaged into the box, running “vagrant” is super fast, you’ll never have to worry about your environment breaking with updates, and you won’t need Internet to code.

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Bringing Scotch Box Up

scotch

Once you’ve run vagrant up, you’ll be able to access your site at http://192.168.33.10/, you should see something similar to the image below.

Useful Stuff in Scotch Box

  • PHP 5.5
  • No Internet connection required
  • PHP errors turned on
  • Laravel and WordPress ready (and others)
  • Operating System agnostic
  • Goodbye XAMPP / WAMP
  • New Vagrant version? Update worry free. ScotchBox is very reliable with a lesser chance of breaking with various updates
  • Bootstrap and jQuery are saved in the server’s home folder in case you don’t have Internet (usually plains, trains or cars)
  • Chef and Puppet ready in case you want to add extra features on Vagrant Up
  • Super easy database access and control
    MIT License

Server Components Included

  • Apache
  • Vim
  • MySQL
  • PHP 5.5
  • Git
  • Screen
  • Composer
  • cURL
  • GD and Imagick
  • Mcrypt
  • Memcache and Memcached

Front End Stuff Included

  • NPM
  • Grunt
  • Bower
  • Yeoman
  • Gulp
vagrant-ssh

You can SSH to your server as well, by running vagrant ssh. Upon logging in via SSH you’ll see something similar to the image below.

Scotch Box is in its infancy still. It’s initial commit to GitHub was on October 6, 2014 and has about 10 commits in total.

Updating Scotch Box is easy too. To check for an updated version with Vagrant, do vagrant box outdated. That will tell you if there’s a newer version available. If there is a newer version available, you can update to it by running vagrant box update.

Head to the official Scotch Box website for more information on setting up databases, setting a hostname, and for more details on updating the box. Some basic Vagrant commands are also included to help you with basic Vagrant usage (ie: pausing, resuming, or destroying a server).

If you’re a LAMP developer like I am, and are tired of developing on your client’s dev servers, Scotch Box could be a good solution for you to develop locally. It’s sometimes much easier to develop locally then having to rely on a slow dev server provided by your client. :)

All the images in this post are included in the gallery below.

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Send Apache Logs to Papertrail With Rsyslog

Over the last few days, I’ve been looking at Apache web server logs, a lot, mostly quick checks for Shellshock probes and exploit attempts. All on client servers, thankfully. All of the servers I operate through DigitalOcean are patched up. It just so happens that all the sites I host have their DNS hosted by Cloudflare, which has been blocking all Shellshock attempts.

A majority of my sites send their Apache logs to Papertrail. Having all my apache logs easily accessible and searchable is extremely nice. It’d make sniffing out Shellshock attempts quite simple. You can check for Shellshock attempts relatively easily from the command line, as well, something like the command below would work:

grep '() {' /var/log/apache2/access.log

1. Setup Rsyslog to Send to Papertrail

Anyway, sending Apache logs to Papertrail is pretty easy. I’m going to assume you’ve already setup rsyslog to send logs to Papertrail. If not, this post should help.

2. Add CustomLog Directive To Your VirtualHost

You just need to modify your virtualhost configuration and add a CustomLog directive. Here’s what I do to send longren.io logs to Papertrail:

CustomLog "| /usr/bin/logger -t httpd -p local1.info" "%{%b %d %X}t longren.io apache %h %l %u %t "%r"%>s %b "%{Referer}i" "%{User-agent}i""

The -t httpd piece sets the service name for Papertrail. The -p local1.info flag sets the priority. You’ll want to change the longren.io piece in the above code to whatever site you’re capturing logs for. You can also change or remove apache that immediately follows longren.io.

3. Reload Apache

After you’ve added the CustomLog directive to your virtualhost, you’ll want to reload Apache:

sudo service apache reload

That’s all there is to it. You should start seeing your Apache logs in Papertrail shortly after reloading Apache.

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TinyCert: Generate SSL Certificates And Become Your Own Certificate Authority

A few days ago I moved longren.io to https. I didn’t pay for a certificate though like I would when setting up an e-commerce site or something else important.

I even get the little green lock symbol in the address bar, but I think this is mostly due to my use of Cloudflare.

TinyCert is a service I discovered that lets you be your own PKI/certificate authority. It’s entirely free and provides you with a very nice interface for managing your certificates. The image below shows the interface for managing your certificates. The list on the right is a list of certificates, as you can see I’ve got one made up for longrendev.io, but haven’t put it in place quite yet.
tinycertinterface

The support from TinyCert is very good as well, I had a few questions regarding how their certificates would work with Cloudflare and they quickly cleared my questions up. SSL Labs from Qualys gives the SSL certificate an “A” rating. Should you use certificates from TinyCert in production? Probably not. I am, however, due to my use of Cloudflare.
ssl

This post isn’t meant to show you how to install certificates or use TinyCert, it’s simply to make you aware of the tool and what can be done with it. TinyCert has a pretty extensive FAQ, so should you have questions, which I’m sure you do, head on over and start reading. If you do need help installing the certificates from TinyCert, their help center does a nice job of providing instructions for Apache and Nginx based setups.

Have fun with TinyCert, it’s a pretty awesome service that I’ll continue to use and will absolutely be donating to. But please remember, TinyCert certificates should not be used for regular public websites and the service is not a substitute for a proper certification authority, but for self-signed certificates.

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Automate Taking Snapshots of Your DigitalOcean Droplets with DOSnapshot

Multi-threading. Auto-cleanup. Cron optimized.

There are a lot of neat tools people have built for DigitalOcean.

The app I’m really in love with is DOSnapshot, and is hosted on GitHub. DOSnapshot does exactly what its name would suggest, it takes snapshots of your droplets.

As of this post, I’m the only one that’s left a comment on the DOSnapshot Community Projects page, which took me a bit by surprise, given the quality of the tool.

Taking a snapshot of a DigitalOcean Droplet is essentially like making an exact copy of the Droplet (server) that you can then use again at a later time. Very useful for scaling and updating a Droplet to a newer version of your Linux distribution without losing all of the Droplet’s configuration.

Etel Sverdlov does a very good job of explaining the difference between snapshots and backups in this DigitalOcean community tutorial. I suggest you read it if you’re unsure what the differences between a backup and snapshot are.

1. Install DOSnapshot

DOSnapshot can be installed as a ruby gem, which is what I chose to do because it’s just so easy. Don’t install this on your DigitalOcean Droplet! It’s meant to run from your local machine. Installing DOSnapshot as a Rubygem is as simple as: 

sudo gem install do_snapshot

Pre-built binaries are also provided for Linux users, and OSX users have the option of installing via Homebrew Tap.

2. Set Your DigitalOcean Client ID and API Key

Once you’ve got it installed, you’ll need to set your DigitalOcean Client ID and API Key. You can set them as environment variables, or you can pass them as parameters when actually running DOSnapshot. This is straight from the README:

First you may need to set DigitalOcean API keys:

$ export DIGITAL_OCEAN_CLIENT_ID=”SOMEID”
$ export DIGITAL_OCEAN_API_KEY=”SOMEKEY”

If you want to set keys without environment, than set it via options when you run do_snapshot:

$ do_snapshot –digital-ocean-client-id YOURLONGAPICLIENTID –digital-ocean-api-key YOURLONGAPIKEY

3. Take A Snapshot

Please remember that running the do_snapshot command will cause your droplet to shutdown so the snapshot can be taken.

DOSnapshot has a pretty large number of options that you can specify. I’m going to keep this simple so you get the basics of it. Learning a few of the main options will be mostly what you need to know, after you’ve got them figured out, setting up a cronjob is cake.

You can take snapshots of all of your droplets at once, you can specify which droplets to take snapshots of, and you can specify droplets that you don’t want to take a snapshot of. I typically take a snapshot of a single droplet at a time, and I do it like this: 

do_snapshot --only 1111 -k 3 -c -v

The above will take a snapshot of only one droplet, a droplet with an ID of 1111, replace 1111 with the ID of your droplet. You can find your droplets ID in your browser URL bar while managing the droplet. So if you see https://cloud.digitalocean.com/droplets/1234567, your droplet’s ID is 1234567.

Here’s all of the options.

4. Scheduling With Cron

First, you must have cron installed. There’s plenty of tutorials on how to do that. That tutorial even explains how to configure a cron job using the crontab utility. There’s an example crontab entry in the DOSnapshot README. Mine is pretty simple: 

0 4 * * 2 do_snapshot --only 1111 -k 3 -c -v

If you have questions about setting any of this up, feel free to leave a comment!

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