Instagram Multi-factor authentication Bypass

vishnuraj
vishnuraj
Nov 27, 2018 · 2 min read

Hi ,

This post is regarding one of my findings in Facebook, which could have allowed anyone to bypass Multi-factor authentication.

Vulnerability Type :

Privilege Escalation/bypass authorization

Product Area:

Instagram

Description

Two-factor authentication is a security mechanism that requires two types of credentials for authentication and is designed to provide an additional layer of validation, minimizing security breaches.

Impact

Two-factor authentication can be bypassed using the add instagram account feature in facebook business . While merging the victim account with the attacker facebook account, 2FA of victim account gets automatically bypassed which an attacker use 2fa enabled victim account without entering 2FA process.

Proof of Concept

1) User “A” creates a business account and Adds victim Two-factor authentication enabled account.

Image for post
Image for post

2) add victim username and password (2FA enabled account)

Image for post
Image for post

3) here you can see 2FA check skipped when a Business Manager tries to link an Instagram Account

Image for post
Image for post

I would like to thanks Facebook Security Team for this awesome Response .

Image for post
Image for post

Thanks again!

Have a great day ahead ☺

Welcome to a place where words matter. On Medium, smart voices and original ideas take center stage - with no ads in sight. Watch
Follow all the topics you care about, and we’ll deliver the best stories for you to your homepage and inbox. Explore
Get unlimited access to the best stories on Medium — and support writers while you’re at it. Just $5/month. Upgrade

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store