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One does not simply add MFA

November 29, 2022

One does not simply add MFA


November 29, 2022

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  1. @[email protected]
    One does not simply add MFA

    Just like a walk into Mordor, good MFA is a journey

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  2. @[email protected]
    What you will learn
    ✓ What is MFA

    ✓ How to secure your

    ✓ What are the MFA types

    ✓ How to protect users and
    secure an application

    ✓ Potential testing steps

    ✓ MFA implementation best
    "Its black gates are guarded by more than just orcs. "

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  3. @[email protected]
    Taking notes or pictures 📝

    Asking foolish questions 🤔

    Things you don't need to worry about
    "There is evil there that does not sleep, and the Great Eye is ever watchful"

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  4. Let our journey begin…

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  8. @[email protected]
    Back to the beginning
    To when you signed up for

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  13. @[email protected]
    What was the
    hacker up to?
    Calling your mobile provider

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  14. @[email protected]
    On the phone
    with your mobile
    Using social engineering

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  15. @[email protected]
    Now they have
    all the access...
    Sim swap/sim hijacking

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  17. @[email protected]

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  19. @[email protected]
    We learned that SMS-based
    authentication is not nearly as
    secure as we would hope, and the
    main attack was via SMS intercept

    Christopher Slowe

    Reddit chief technology of
    cer and founding engineer

    August 2018

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  20. @[email protected]
    What is authentication?
    The process of verifying that someone or
    something is the actual entity that they claim
    to be.

    - OWASP.org

    (these people know what they are talking about when it comes to security)

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  21. @[email protected]
    ... but what are the different factors of auth?
    ✔Factor is knowledge (i.e. your password)

    ✔Is the other method choice

    - Possession (token/soft token)

    - Identity (biometrics)

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  22. @[email protected]
    2FA = 2SV = MFA = 2F? = ???

    What about all those other acronyms...

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  23. @[email protected]
    Why didn't MFA help?
    •SMS was used

    •For most users MFA won’t even be enabled

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  24. @[email protected]
    • Most common

    • Most compromised

    • Not recommended
    by NIST since 2016

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  25. @[email protected]
    If SMS wasn't bad enough
    •SS7 (network shared by every telecom) has
    it's own vulnerabilities

    •Text messages that are sent can be

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  26. @[email protected]
    Let's figure out
    all the ways to
    hack it...
    1. Sim-swap (aka what just
    happened to us)
    2. Port-out scam
    3. Brute force on the
    application itself
    4. Exploit SS7 weakness

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  27. @[email protected]
    • Associated with certain
    authorized devices

    • Not visible on a locked
    phone screen
    Push Based

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  28. @[email protected]
    … Push Based has
    major drawbacks too
    September 15th, 2022

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  29. @[email protected]
    Security Questions
    • User answers a set of questions during sign-up

    • For example

    • Merry’s mother’s maiden name?

    • What is the shire’s address?

    • Just an extension of your first factor, password
    ❓ ❓

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  30. @[email protected]
    • At login time, an email with verification
    code is sent to user

    • Convient

    • Should only be used with verified emails

    • Less Common, may be in use but may
    not referred to as MFA

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  31. @[email protected]
    Example email verification step

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  32. @[email protected]
    Time-based One Time Password

    aka app based

    aka soft token

    • Authy

    • Google Authenticator

    • 1Password

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  33. @[email protected]
    Token based
    Physical keys that can auth

    • FIDO2/WebAuthn

    • USB drive

    • near-
    eld communication

    • Many use U2F (Universal
    2nd Factor)

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  34. @[email protected]
    OTP vs U2F

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  35. @[email protected]
    OTP U2F
    • User has physical device

    • Strong security from
    public key cryptography

    • No personal information
    associated with a key
    • Users type in codes

    • Set up and provision required

    • Secrets stored, providing a
    single point of attack

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  36. What would you change now?

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  37. @[email protected]
    Secure Your Account
    1. Use long password/passphrase

    2. Secure with alternate authentication method

    3. Use a VOIP number

    4. Don't reuse passwords

    5. Pin/password protect phone provider

    Keep on being @awesome

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  38. @[email protected]
    … now let’s put a
    twist on our story

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  39. @[email protected]
    Not that twist...
    Now you are the developer at shiregram (an insta rival)

    How do you secure your users from all the bad stuff
    out there?

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  40. @[email protected]
    • Developers

    • Designers

    • Infrastructure

    • Managers

    • Not just info sec!
    Security is everyone's job

    MY JOB TOO!?

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  41. @[email protected]

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  42. @[email protected]

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  43. @[email protected]
    Back to your security basics
    1. Strong passwords/passphrase 💪

    2. Don't make them be rotated 🔁

    3. Store the hash securely 🔒

    4. Only store sensitive data that you need ⛔

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  44. https://xkcd.com/936/ @[email protected]

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  45. @[email protected]
    Why this helps
    •Greater entropy = harder to brute force the password

    •Passwords should be hard to guess, but easy to remember

    •Extra length + randomness allows for more entropy

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  48. Do this 😄

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  51. Not this 😞

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  52. ⬆ that is 6 a's

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  53. Not this

    either 😧

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  54. @[email protected]
    Let's talk about password hash encryption
    • Just an algorithm that takes data and produces fixed-size output

    • Some hashes are stronger then others

    • MD5/SHA-1 = 👎

    • SHA-256/512-bit SHA-2= 👍

    • If possible with performance, use an adaptive one-way function

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  55. @[email protected]
    Strong recommended adaptive functions




    Head on over to OWASP.org for more details

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  56. @[email protected]
    …we made the decision to rotate customer
    accounts on May 5, 2022, out of an abundance
    of caution due to not all of the customers
    having multi-factor authentication (MFA)
    enabled at the time and potential for password

    Bob Wise

    Heroku General Manager and Salesforce

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  57. @[email protected]
    ...a user lost their phone/app access/token
    • Recovery codes to
    the rescue! 🦹

    • Allows access to

    • Shown once, used

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  58. Choose your path

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  59. @[email protected]
    If you choose to BUY
    •Choose your vendor wisely

    •What factor choices are available?

    •What are your authorization and
    authentication needs?

    •Can you export your data?

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  60. @[email protected]
    If you choose DIY
    More flexibility
    More security surface area to cover
    More control over the user experience

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  61. Somethings to keep in mind no matter your path…

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  62. @[email protected]
    Rate limiting
    prevents brute
    force attacks
    Rate limiting prevents brute force attacks

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  63. @[email protected]
    Use a truncated exponential back-off algorithm
    Uh wut now?

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  64. @[email protected]
    What is an exponential back-off algorithm?

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  65. @[email protected]
    Get user buy-in

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  66. @[email protected]
    ✓ Make it easy opt in

    ✓ Make it easy to add
    ✓ Make it visible

    ✓Make it flexible
    Make it easy on your users

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  67. @[email protected]
    Not this 😢
    American Express







    Best Buy

    State Farm


    Twitter (well not right now)
    🚫 MFA

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  68. @[email protected]
    Do this 😄

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  69. @[email protected]
    • For editing/removing of
    MFA require credentials

    • If authentication does
    fail, be generic in error
    More authentication

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  70. Do this

    "Login failed - invalid user ID or password"


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  71. Not this

    "Login for User awesome: invalid password"

    "Login failed, invalid user ID"

    "Login failed; account disabled"

    "Login failed; this user is not active"


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  72. @[email protected]
    Are we doing all we can to protect our users?

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  74. @[email protected]
    Users with the most amount of
    privilege, 2FA is a requirement
    not optional

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  76. @[email protected]
    MFA can help but...
    Can only improve security if you are following secure
    password practices
    Some MFA methods are more secure then others

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  78. Thanks for having me WP Engine Omaha friends!

    Thanks to:

    Tyson Reeder for the final graphic


    For references and further reading checkout


    Find me on mastodon @[email protected]

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  79. @[email protected]
    What questions can I answer?

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  80. code!!

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  81. @[email protected]
    Twilio API Example

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  82. @[email protected]
    The Ruby One Time Password Library Example

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  84. @[email protected]
    But you need to
    get this code to
    your user...

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  85. @[email protected]
    Authy One Touch API Example

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  86. @[email protected]
    QR Code Rendering
    Twilio Ruby API
    Auth Ruby API

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