A New Book: BYOD for You

byod for you cover

Most BYOD guides we’ve seen cover BYOD from management’s or the IT department’s point of view; BYOD for You is the first we’ve seen that covers it from the rank-and-file employee’s angle. Written by Daniel Lohrmann, who blogs at Government Technology and has a site at, this Kindle ebook is a quick read that helps you determine an organizations BYOD maturity level, secure your BYOD mobile device and maximize its benefits, and how to cope with the way personal mobile devices are handled where you work.

BYOD for You is an easy lunchtime read; it’s divided into eight chapters, most of them about a half-dozen pages long, which cover these topics:

  1. Categorizing your BYOD enivronment: Gold, Silver or Bronze?
  2. Your workplace’s BYOD program, or the lack thereof
  3. Security: How to safely use your mobile device at work and home
  4. MDM
  5. Privacy and other legal considerations
  6. Maximizing the financial benefits of BYOD
  7. Ethical dilemmas and proving you deserve your mobile device
  8. Building a personalized BYOD plan that outlives your device

Each of the chapters end with a section that provides suggestions on how to handle its topic depending on the BYOD maturity level of your organization. Lohrmann’s model for BYOD maturity has three levels, which are explained below:

  • Bronze: An organization operating at the Bronze BYOD level has employees who bring their own devices to work, but doesn’t have an official BYOD policy. It’s unclear about what happens when company information security policies and personal devices collide, if employees’ personal data will remain private, or if their work-related activities on personal devices will get them in trouble. Employees also bear all costs of using the device, even for work-related purposes. MDM is practically or completely non-existent.
  • Silver: In organizations operating at the Silver BYOD level, there is a basic BYOD policy that spells out how its data can be accessed, as well as issues of security and privacy, and there is tacit permission for employees to access their work email from their devices. Employees can choose between all-expenses-paid COPE devices or BYOD devices without any reimbursement for operating costs. MDM is limited; it’s often something basic, like what’s provided by Microsoft Exchange ActiveSync.
  • Gold: At the Gold level of BYOD, there’s a full BYOD policy, and employees are fully reimbursed for all device costs. All devices are under full MDM.

Even though it’s written for end users at a workplace, it’s a useful guide for managers who are new to the idea of BYOD and want to get a grasp of the major issues that can arise when employees bring their own devices to work. I expect that we’ll be using this in our consulting work and recommending it to our customers.

There’s a special deal if you buy it today (Wednesday, April 17, 2013): it’s selling at a dollar off — a mere CAD$3.03 at, and USD$2.99 at

BYOL: Bring Your Own Liabilities


Mobile technologies bring new capabilities, but new complications as well. The CIO article BYOL: Bring Your Own Liabilities points out that the dual nature of BYOD devices — owned by the employee, but used part of the time on behalf of the company (and possibly subsidized) — present some new potential legal issues, whether or not your organization has a formal BYOD program. The article lists a number of ways you can reduce the risk of legal exposure in your BYOD program; the article goes into more detail, and we’ve summarized the main points below:

  • Policy: The article says that a policy defining your organization’s BYOD program is most important element of any BYOD strategy, and we’re inclined to agree. Such a policy should clearly define how your BYOD program will operate, specify the risks and responsibilities of the organization, employees and third parties, and define acceptable technologies and acceptable use. Most of it shouldn’t have to address legal issues, but having such a policy will help reduce your legal exposure. (By the bye, we’re pretty good about crafting mobile device policies, and we even have a guidebook to help you build your own.)
  • Liability issues: Figure out whether your organization or your employees are liable in certain cases, such as: Who’s responsible for misplaced or stolen devices? Who’s responsible in the event of a malware attack? Who pays for support?
  • Licensing: Are the apps on mobile devices — both company- and employee-owned — properly licensed?
  • Insurance: Will your organization’s insurance policy cover devices that it doesn’t directly own or lease?
  • Data security: As the article says: “Two topics generally colour the legal framework in the context of data security; these are confidential information and litigation obligations, both of which are concerns for any mobility based system.”
  • Confidentiality: We take our mobile devices (especially our smartphones) everywhere, and sooner or later, they’ll get lost or stolen. You need to consider the implications of missing mobile devices, from the loss of your organization’s sensitive information, to inadvertent breaches of confidentiality agreements with other parties, to remote wipes, to the consequences of remotely wiping an employee’s personal data. Along with the issues that come with confidential or sensitive data on the device, there’s also the issue of such data off the device, stored with third-party cloud services like Dropbox.
  • Discovery obligations: Data stored on mobile devices used for work may be subject to electronic discovery, the pre-trial phase in litigation where each party can get evidence from the opposing party. You may need to take measures to keep work and personal data separate, keeping in mind that your organization can’t object to producing some information in the discovery process simply because it has some personal employee information mixed in.
  • Privacy: One reason to try to keep work and personal data separate is to preserve employee privacy, especially when backing up information. Ideally, you want to back up only the work-related information and store no personal employee information (such as their address book or photos) on your organization’s backup system.
  • Surveillance and tracking: The ability to remotely track a device is a useful thing to have when it’s lost or misplaced, but it can be a cause for concern about its use for tracking employees. The article recommends the use of a data surveillance policy that clearly spells out how devices will be tracked, and if your organization will record information stored or transmitted by the device.

BYOD and Shadow IT

the shadow strikes

From an earlier article:

Shadow IT sounds like some kind of future slang that [William] Gibson would’ve coined, but it’s an office term referring to the set of applications and systems that are used in organizations without that organization’s approval, and especially without the approval of the IT department. It’s usually the result of one or a handful of employees discovering an application, service or system that solves a problem in a way that seems more effective, expedient, and more free of red tape than if it were solved by IT. Shadow IT usually starts off as an ad hoc solution, but if it becomes popular within an organization, its use can become standard practice, even without the approval or oversight of the IT department.

When people talk about shadow IT, they usually talk about the security issues. Mike Foremen in Huffington Post UK writes about another equally important issue: the creation of data silos, where information vital to the business lives in places where it can’t be found.

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Salmagundi for Thursday, December 15, 2011

by Joey deVilla on December 15, 2011

salmagundi smallSalmagundi? That’s the word for a seventeenth-century English dish made of an assortment of wildly varying ingredients. Typically, they include some cut-up hard-boiled egg, but then after that, anything goes: meat, seafood, fruits and veg, nuts and flowers and all manner of dressings and sauces. The term comes from the French “salmigondis”, which translates as “hodgepodge”.

In this case, I’m using “salmagundi” as a term for a mixed bag of new items that you might find interesting as a developer.

The Tangled Web: A Guide to Securing Modern Web Applications

tangled web

I’m currently in the middle of reading Michal Zalewski’s new book, The Tangled Web: A Guide to Securing Modern Web Applications and it’s been a fascinating, enlightening and enjoyable read. At first glance, you might be tempted to simply sum it up as a “security book”; I think it’s more accurate to describe it as “a great review of how browsers, their protocols, programming languages and security features work, and how to write secure apps given this knowledge”. Given that web security is a rapidly moving target, especially with the browser vendors – even the formerly-pokey Microsoft – cranking out versions at a faster rate, Zalewski’s approach to the topic is the right one: make sure the reader is clear on the basic principles, and then derive the security maxims from them, giving the knowledge contained within the book a much longer “shelf life”.

The Tangled Web is divided into three parts:

  1. Anatomy of the web. A tour of the web’s building blocks, from URL structure, HTTP and HTML to how it’s all rendered: CSS, client-side scripting languages, non-HTML documents and plug-ins.
  2. Browser security features. All the mechanisms that keep the malware from 0wnz0ring your system – the same-origin policy, frames and cross-domain content, content recognition mechanisms, dealing with rogue scripts and extrinsic site privileges (that is, privileges that aren’t derived from the web content, but from settings within the browser).
  3. A glimpse of things to come. A look at some of the proposed security mechanisms and approaches that may or not become standard parts of the web.

Each chapter except the last ends with a “Security Engineering Cheat Sheet”, which functions as both a summary of the material within the chapter and a security checklist. The last chapter is titled Common Web Vulnerabilities and lists vulnerabilities specific to web application, problems to keep in mind when designing web apps and common problems unique to server-side code.

I’m going to be showing The Tangled Web around the office (especially now, since I’m physically in Shopify’s headquarters this week). I’m sure the developers know a lot of this stuff, but they’re a bunch who are always eager to learn, review and “sharpen the saw”, so I think they’ll find it useful. If you develop web apps, whether for fun or to pay the rent, you’ll want to check out this book as well.

CUSEC 2012: Montreal, January 19 – 21

turing complete

Ah, CUSEC: the Canadian University Software Engineering Conference. This for-students-by-students conference punches well above its weight class. I’ve been to tech conferences put on by so-called full-time “professionals” that can’t hold a candle to what the students behind CUSEC do every year in addition to their course loads.

Better yet is the caliber of speakers they’ve been able to bring in: Kent Back, Joel Spolsky, David Parnas, Greg Wilson, Chad Fowler, Kathy Sierra, Dave Thomas, Venkat Subramanian, Jeff Atwood, Tim Bray, John Udell, Avi Bryant, Dan Ingalls, Giles Bowkett, Leah Culver, Francis Hwang, Doug Crockford, Matt Knox, Jacqui Maher, Thomas Ptacek, Reg Braithwaite, Yehuda Katz, of course Richard M. Stallman, in whose auction I made the winning bid for a plush gnu, which I paid with my Microsoft credit card.

alan turingThis year’s CUSEC theme is “Turing Complete” in honor of 2012 being the 100th anniversary of Alan Turing. He established his place in history as the father of computer science by formalizing concepts like “algorithm” and “computation” with the concept of the Turing Machine, proposing the Turing Test in an attempt to answer the question “Can machines think?”, working as a codebreaker at Bletchley Park (I like to say “He beat the Nazis…with math!”) and coming up with one of the first designs for a stored-program computer. He even found his way into pop culture by getting name-checked in Cryptonomicon and The Social Network.

Once again, Shopify will be there as a sponsor and once again, I will be hosting the DemoCamp at CUSEC. If you’re a university student studying computer science or computer engineering, you should come to Montreal from January 19th through 21st and catch one of the best conferences you’ll ever attend. Bring your resume: we’re looking for talented programmers who want to work us!



Cat pictures meet motivational posters meet HTTP status codes! It’s the Perfect Storm!


This article also appears in the Shopify Technology Blog.


The ASP.NET Security Vulnerability

Poster for the movie "Hackers"

Chances are that you’ve seen the Microsoft Security Advisory, but in case you haven’t here’s the "tl;dr" version:

  • There’s a vulnerability in ASP.NET that was publically disclosed late on Friday at a security conference.
  • An attacker using this vulnerability can:
    • Request and download files within an ASP.NET application like the web.config file (which often contains sensitive data).
    • Decrypt data sent to the client in an encrypted state (like ViewState data within a page).

How Does the Vulnerability Work?

The vulnerability is based on a cryptographic oracle. When talking amongst the crypto crowd, an “oracle” refers to a system that gives away hints if you ask it the right questions.

Within ASP.NET, there’s a vulnerability that acts like a “padding oracle”. An attacker can send ciphertext to the web server and learn if it was decrypted properly by looking at the error code returned by the server. Make lots of requests like that while keeping track of the error codes returned, and you can learn enough to decrypt the ciphertext.

How Do You Work Around the Vulnerability (the high-level version)?

The vulnerability works because of the different error codes returned by the server. The workaround is to change the error handling withing ASP.NET so that it always sends the same error each time, regardless of the error, thereby cancelling the “oracular” behaviour.

More specifically, this involves enabling the <customErrors> feature of ASP.NET and mapping all errors to return the same error page.

How Do You Work Around the Vulnerability (the step-by-step version)?

Scott Guthrie’s blog has the step-by-step instructions for:

  • Working around the vulnerability
  • Making sure that the workaround has been enabled
  • Finding vulnerable ASP.NET applications on your server
  • Finding out more about the vulnerability

If you’ve got an ASP.NET-based application, make sure you’ve set up the workaround!

This article also appears in Canadian Developer Connection.


The “500 Worst Passwords”

by Joey deVilla on March 29, 2010

Hand-drawn list of the "500 Worst Passwords"

You’ve heard the stories about people choosing terribly obvious passwords for their various computer accounts, such as “password” and “12345”, but what are the other ones? In his book, Perfect Passwords: Selection, Protection, Authentication, Mark Burnett compiled the most common easy-to-crack passwords, most of which are ordinary words or key sequences that are easy to type on a QWERTY keyboard. I’m amused by some of the pop culture-based passwords, such as “Rush2112”, “8675309” and the X-Files inspired “TrustNo1”.

Someone else — I don’t who who did it — decided to turn that list into the hand-lettered poster shown above. You can click it to see it at a larger size.

In addition to being a good list showing the sort of password you shouldn’t use, it’s also a great name generator. You could take two random items from the list to create new character names for a Metal Gear game (“Tomcat Eagle1” makes just about as much sense as “Solid Snake” or “Sniper Wolf”) or any three to come up with the name of your band or prison softball team (“Bigdick Magnum Juice”).

This article also appears in The Adventures of Accordion Guy in the 21st Century.


Renault with a banner across its bumper reading "ZU 0666', 0, 0); DROP DATABASE TABLE LICENCE;"Click the photo to see it at full size.

“Flintstones/Jetsons” is a term that Mark Mothersbaugh from Devo uses to describe technology solutions that are a combination of low- and high-tech. It’s probably an apt term for what the driver of the Renault in the photo above is doing to foil licence plate cameras. If the “Jetsons” part – the SQL injection attack comprising the text on the banner on the bumper – doesn’t work, the “Flintstones” approach of physically covering up the licence plate will.

SQL Injection-a-Rama

No quick tour of SQL injection is complete without mentioning this classic XKCD comic, Exploits of a Mom. If you’ve ever heard someone use the phrase “Little Bobby Tables” when talking about databases and security, here’s where it comes from:

The classic "Little Bobby Tables" XKCD comic.

"SQL" with a syringe sticking through it

Want a good introduction to SQL injection attacks? Start with SQL Injection Attacks by Example at Steve Friedl’s Tech Tips. It walks you through the steps of an SQL injection attack, where a cracker (note that I said “cracker” – there are hackers and crackers, and there’s a difference) uses a combination of deductive reasoning and unexpected, unsanitized input to get unintended results from the database.

Also worth checking out:

Here’s an enjoyable presentation by Joe McCray on Advanced SQL Injection, which he gave at the 2009 LayerOne conference. He likes to drop the “f-bomb” and “s-bomb” every now and again while presenting, but if you don’t mind a little salty language, it’s a good security talk:

(You can download the slides from Joe’s presentation in PDF format here.)

This article also appears in Canadian Developer Connection.


Congrats, “Mudge”, on Landing the DARPA Gig!

by Joey deVilla on February 10, 2010

imageI met Peter “Mudge” Zatko at the Cult of the Dead Cow’s hotel bungalow at DefCon 8, the 2000 edition of the notorious hacker conference. My coworker at OpenCola, Oxblood Ruffin, was a member of the the “cDc” and introduced me and the other OpenColans to him and the other nicknames in the group: “Sir Dystic”, “Dildog”, “Deth Veggie”, “Night Stalker”, “Grandmaster Ratte” and many other black-clad, charmingly oddball characters far more interesting than the characters in the movie Hackers. I think I learned more about security in the hour-long group conversation with him than I’ve learned from countless corporate security training videos and training courses. Later at the conference, the cDc would hand out more copies of Back Orifice 2000, a tool that would cause much heartburn to many people at the company where I now work.

He’s now got a big gig: Program Manager at the Strategic Technologies Office at DARPA, the Defense Advanced Research Projects Agency, the R&D office for the Department of Defense. His area of focus? Security, naturally.

Mudge was responsible for the early research into buffer overflow attacks and published one of the first papers on the topic. In 1998, he and others from L0pht Heavy Industries (a.k.a. “The L0pht”, a hacker think tank) testified before a Senate committee, saying that they could take the internet down in 30 minutes. L0pht was acquired by the security company @stake in 1999, and in 2000, the company where I worked, OpenCola, hired them to do some security consulting. He’s met with President Clinton to talk about DOS attacks and worked at BBN as a division scientist.

I’m curious to see what Mudge can do with government gear and a big budget. In the cnet article, he talks about actively responding to threats. "I don’t want people to be putting out virus signatures after a virus has come out," he says. "I want an active defense. I want to be at the sharp pointy end of the stick."

Do not mess with his pointy end! Congrats, Mudge!


Videos from the 2009 RSA Conference

by Joey deVilla on May 15, 2009

This article also appears in Canadian Developer Connection.


The 2009 edition of the RSA Conference, the biggest and best-known cryptography and information security conference, took place last month in San Francisco. Each year, the conference has a theme based on or relevant to crypto or infosec, and this year’s theme was Edgar Allen Poe (previous themes include the Navajo Code Talkers of World War II, the secrets of the Mayans, Mary Queen of Scots and Alan Turing).

Adam Savage and Jamie Hyneman at their keynote at the 2009 RSA Conference

The people behind the conference were kind enough to post video of the keynotes, which I found thanks to a pointer from TechNet’s Jeff Jones, author of the Jeff Jones Security Blog. You can click on the links below to watch the videos. Jeff strongly recommends that you do not miss the opening ceremony segment of the “Day 1 Keynotes” video, and I don’t have to tell you that you should catch the closing keynote, featuring Adam Savage and Jamie Hyneman of the popular nerd television series Mythbusters: