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Andrea Veri: Adding reCAPTCHA support to Mailman

Planet Ubuntu - Sat, 2014-05-03 09:37

The GNOME and many other infrastructures have been recently attacked by an huge amount of subscription-based spam against their Mailman istances. What the attackers were doing was simply launching a GET call against a specific REST API URL passing all the parameters it needed for a subscription request (and confirmation) to be sent out. Understanding it becomes very easy when you look at the following example taken from our apache.log:

May 3 04:14:38 restaurant apache:, - - [03/May/2014:04:14:38 +0000] "GET /mailman/subscribe/banshee-list? HTTP/1.1" 403 313 "http://spam/index2.html" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/34.0.1847.131 Safari/537.36"

As you can the see attackers were sending all the relevant details needed for the subscription to go forward (and specifically the full name, the email, the digest option and the password for the target list). At first we tried to either stop the spam by banning the subnets where the requests were coming from, then when it was obvious that more subnets were being used and manual intervention was needed we tried banning their User-Agents. Again no luck, the spammers were smart enough to change it every now and then making it to match an existing browser User-Agent. (with a good percentage to have a lot of false-positives)

Now you might be wondering why such an attack caused a lot of issues and pain, well, the attackers made use of addresses found around the web for their malicius subscription requests. That means we received a lot of emails from people that have never heard about the GNOME mailing lists but received around 10k subscription requests that were seemingly being sent by themselves.

It was obvious we needed to look at a backup solution and luckily someone on our support channel suggested the sysadmins recently added CAPTCHAs support to Mailman.  I’m now sharing the patch and providing a few more details on how to properly set it up on either DEB or RPM based distributions. Credits for the patch should be given to Debian Developer Tollef Fog Heen, who has been so kind to share it with us.

Before patching your installation make sure to install the python-recaptcha package (tested on Debian with Mailman 2.1.15) on DEB based distributions and python-recaptcha-client on RPM based distributions. (I personally tested it against Mailman release 2.1.15, RHEL 6)

The Patch diff --git a/Mailman/Cgi/ b/Mailman/Cgi/ index 4a54517..d6417ca 100644 --- a/Mailman/Cgi/ +++ b/Mailman/Cgi/ @@ -22,6 +22,7 @@ import os import cgi +import sys from Mailman import mm_cfg from Mailman import Utils @@ -30,6 +31,8 @@ from Mailman import Errors from Mailman import i18n from Mailman.htmlformat import * from Mailman.Logging.Syslog import syslog +sys.path.append("/usr/share/pyshared") +from recaptcha.client import captcha # Set up i18n _ = i18n._ @@ -200,6 +203,9 @@ def list_listinfo(mlist, lang): replacements[''] = mlist.FormatFormStart('listinfo') replacements[''] = mlist.FormatBox('fullname', size=30) + # Captcha + replacements[''] = captcha.displayhtml(mm_cfg.RECAPTCHA_PUBLIC_KEY, use_ssl=False) + # Do the expansion. doc.AddItem(mlist.ParseTags('listinfo.html', replacements, lang)) print doc.Format() diff --git a/Mailman/Cgi/ b/Mailman/Cgi/ index 7b0b0e4..c1c7b8c 100644 --- a/Mailman/Cgi/ +++ b/Mailman/Cgi/ @@ -21,6 +21,8 @@ import sys import os import cgi import signal +sys.path.append("/usr/share/pyshared") +from recaptcha.client import captcha from Mailman import mm_cfg from Mailman import Utils @@ -132,6 +130,17 @@ def process_form(mlist, doc, cgidata, lang): remote = os.environ.get('REMOTE_HOST', os.environ.get('REMOTE_ADDR', 'unidentified origin')) + + # recaptcha + captcha_response = captcha.submit( + cgidata.getvalue('recaptcha_challenge_field', ""), + cgidata.getvalue('recaptcha_response_field', ""), + mm_cfg.RECPTCHA_PRIVATE_KEY, + remote, + ) + if not captcha_response.is_valid: + results.append(_('Invalid captcha')) + # Was an attempt made to subscribe the list to itself? if email == mlist.GetListEmail(): syslog('mischief', 'Attempt to self subscribe %s: %s', email, remote)

Additional setup

Then on the /var/lib/mailman/templates/en/listinfo.html template (right below <mm-digest-question-end>)  add:

<tr> <td>Please fill out the following captcha</td> <td><mm-recaptcha-javascript></TD> </tr>

Make also sure to generate a public and private key at and add the following paramaters on your file:


Loading reCAPTCHAs images from a trusted HTTPS source can be done by changing the following line:

replacements[''] = captcha.displayhtml(mm_cfg.RECAPTCHA_PUBLIC_KEY, use_ssl=False)


replacements[''] = captcha.displayhtml(mm_cfg.RECAPTCHA_PUBLIC_KEY, use_ssl=True)

EPEL 6 related details

A few additional details should be provided in case you are setting this up against a RHEL 6 host: (or any other machine using the EPEL 6 package python-recaptcha-client-1.0.5-3.1.el6)

Importing the recaptcha.client module will fail for some strange reason, importing it correctly can be done this way:

ln -s /usr/lib/python2.6/site-packages/recaptcha/client /usr/lib/mailman/pythonlib/recaptcha

and then fix the imports also making sure sys.path.append(“/usr/share/pyshared”) is not there:

from recaptcha import captcha

That’s not all, the package still won’t work as expected given the API_SSL_SERVER, API_SERVER and VERIFY_SERVER variables on are outdated (filed as bug #1093855), substitute them with the following ones:


That should be all! Enjoy!

Dimitri John Ledkov: X4D Icons released

Planet Ubuntu - Fri, 2014-05-02 23:38
I am releasing some icons under MIT license. They will be hosted at and available for development on GitHub.
I had to create my own icons, as I couldn't find icons of similar nature under a free license. Hopefully others will find these useful as well.

The icons below are all available in PNG, GIF, SVG and EPS. To link to a specific version directly, add .png, .gif, -v.svg or -v.eps to the generic URI (or browse the icons repository to see all versions).

Document type Light Dark HTML 2.0 HTML 3.2 HTML 4.0 HTML 4.01 XHTML 1.0 XHTML 1.1 XHTML Basic 1.0 XHTML-Print 1.0 CSS CSS 1 CSS 2 MathML 2.0 SVG 1.0 SVG 1.1 SVG 1.2 SVG Tiny 1.1 SVG Tiny 1.2 XML 1.0 XML 1.1

Benjamin Kerensa: Unboxing The First Firefox OS Tablet

Planet Ubuntu - Fri, 2014-05-02 19:25

This is the clean little box the tablet comes in

And let’s open the lid and see what’s inside… Look at that nice large display

The back of the tablet is a soft matte feel so not slippery and has a camera

This device comes with a special boot animation since its not a publicly available device yet.

Second boot animation

The familiar Firefox OS first boot screenLet’s get on the Wifi

Setup the timezone Let’s begin the tablet tour

Swipe lessonsMore swipe lessons

And more swiping

And tutorial complete now to play

And that concludes this unboxing!

Want to play with this? Find me at one of the many conferences I’m attending or speaking at this summer.

Jono Bacon: Unwrapping ‘Dealing With Disrespect’

Planet Ubuntu - Fri, 2014-05-02 05:28

With the growth of the Internet and the ease of publishing content, more and more creative minds are coming online to share videos, music, software, products, services, opinions, and more. While the technology has empowered a generation to build new audiences and share interesting things, an unfortunate side-effect has been a culture in which some consumers of this content have provided feedback in a form that is personalized, mean-spirited, disrespectful, and in some cases, malicious.

We have all seen it…the trolls, the haters, the comment boxes filled with venom and vitriol, typically pointed at people just trying to do good and interesting things.

Unfortunately, this conduct can be jarring for many people, with some going as far to give up sharing their creative endeavours so as not to deal with the “wrath of the Internet”.

As some of you will know, this has been bothering me for a while now. While there is no silver bullet for solving these issues, one thing I have learned over the years is how to put negative, anti-social, and non-constructive comments and feedback into perspective.

To help others with this I have written a free book called Dealing With Disrespect.

Dealing With Disrespect is a short, simple to read, free book that provides a straight-forward guide for handling this kind of challenging feedback, picking out the legitimate criticism to learn from, and how to not just ignore the haters, but how to manage them. The book helps put all communication, whether on or offline, into perspective and helps you to become a better communicator yourself.

My goal with the book is that when someone reads something anti-social that demotivates them, a friend can recommend ‘Dealing With Disrespect’ as something that can help put things in perspective.

Go and check out the new website, watch the introductory video, and go and grab the PDF, read it online, or get it for your Kindle. There is also a FAQ.

The book is licensed under a Creative Commons license, and I encourage everyone who enjoys it and finds it useful to share it.


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