Tuesday, February 27, 2024

Facebook & Instagram Flaw Let Anyone Bypass Two-factor Authentication

The lack of rate-limiting in Instagram was discovered by Gtm Mänôz, a security researcher from Kathmandu, Nepal. 

This flaw could have allowed an attacker to bypass Facebook’s two-factor authentication by validating the targeted user’s already-validated Facebook mobile number using the Meta Accounts Center.

Two-Factor Authentication Bypass on Facebook 

The researcher looked at Instagram’s latest “Meta Accounts Center” layout and noticed that the “Personal Details” section allowed users to add their email and phone number to both their Instagram and linked Facebook accounts. This information can then be verified by entering the proper 6-digit code received by email or phone. 

https://miro.medium.com/max/697/1*xAUPLeIpfS3ogx3fZDqYNA.jpeg
Meta Accounts Center Layout

“At the time of reporting, the endpoint verifying the 6-digit code was vulnerable to lack of rate-limit protection allowing anyone to confirm unknown/known email and phone number both in Instagram and linked Facebook accounts”, the researcher explains.

The lack of a rate-limiting feature allowed an attacker to add an already-verified phone number to a target Facebook/Instagram account when Mänôz looked at Instagram’s new layout for “Meta Accounts.”

Facebook generates a one-time code after the user enters their mobile number to confirm their identification.

However, a threat actor may be able to generate unlimited bot traffic to launch a brute-force attack to validate a one-time Facebook PIN to link the accounts, thus bypassing Facebook’s 2FA protections, because of a rate-limiting flaw on Instagram’s endpoint.

According to the researcher, if the phone number was fully verified and 2FA was activated on Facebook, the victim’s account would no longer have 2FA enabled.

Additionally, if the phone number was only partially confirmed, i.e., used for 2FA, the 2FA will be revoked, and the phone number will be deleted from the victim’s account.

A screenshot of an email sent by Meta to a user that says: "We wanted to let you know that your phone number registered and verified by another person on Facebook."
Message from Meta informing that their two-factor protections have been disabled

“Basically the highest impact here was revoking anyone’s SMS-based 2FA just knowing the phone number,” according to Mänôz.

Since then, Meta has resolved the issue and as part of its bug bounty programme, it gave Mänôz $27,000. To avoid being exposed, users should upgrade their apps to the most recent version.

Network Security Checklist – Download Free E-Book

Website

Latest articles

ThreatHunter.ai Stops Hundreds of Attacks in 48 Hours: Fighting Ransomware and Nation-State Cyber Threats

The current large surge in cyber threats has left many organizations grappling for security...

WordPress Plugin Flaw Exposes 200,000+ Websites for Hacking

A critical security flaw has been identified in the Ultimate Member plugin for WordPress,...

Hackers Actively Hijacking ConnectWise ScreenConnect server

ConnectWise, a prominent software company, issued an urgent security bulletin on February 19, 2024,...

Heavily Obfuscated PIKABOT Evades EDR Protection

PIKABOT is a polymorphic malware that constantly modifies its code, making it hard to...

Anonymous Sudan Promoting New DDoS Botnet: Beware

It has come to light that a group known as Anonymous Sudan is actively...

Scattered Spider: Advanced Techniques for Launching High-Profile Attacks

Scattered Spider is a threat group responsible for attacking several organizations since May 2022...

8220 Hacker Group Attacking Linux & Windows Users to Mine Crypto

In a significant escalation of cyber threats, the 8220 Gang, a notorious Chinese-based hacker group, has intensified its attacks...
Guru baran
Guru baranhttps://gbhackers.com
Gurubaran is a co-founder of Cyber Security News and GBHackers On Security. He has 10+ years of experience as a Security Consultant, Editor, and Analyst in cybersecurity, technology, and communications.

Live Account Takeover Attack Simulation

Live Account Take Over Attack

Live Webinar on How do hackers bypass 2FA ,Detecting ATO attacks, A demo of credential stuffing, brute force and session jacking-based ATO attacks, Identifying attacks with behaviour-based analysis and Building custom protection for applications and APIs.

Related Articles