Categories: Cyber Security News

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. 

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.

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

Gurubaran

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.

Recent Posts

Critical TP-Link DHCP Vulnerability Let Attackers Execute Arbitrary Code Remotely

A critical security flaw has been uncovered in certain TP-Link routers, potentially allowing malicious actors…

2 days ago

Chinese SilkSpecter Hackers Attacking Black Friday Shoppers

SilkSpecter, a Chinese financially motivated threat actor, launched a sophisticated phishing campaign targeting e-commerce shoppers…

2 days ago

Cybercriminals Launch SEO Poisoning Attack to Lure Shoppers to Fake Online Stores

The research revealed how threat actors exploit SEO poisoning to redirect unsuspecting users to malicious…

2 days ago

Black Basta Ransomware Leveraging Social Engineering For Malware Deployment

Black Basta, a prominent ransomware group, has rapidly gained notoriety since its emergence in 2022…

2 days ago

Critical Laravel Vulnerability CVE-2024-52301 Allows Unauthorized Access

CVE-2024-52301 is a critical vulnerability identified in Laravel, a widely used PHP framework for building…

2 days ago

4M+ WordPress Websites to Attacks, Following Plugin Vulnerability

A critical vulnerability has been discovered in the popular "Really Simple Security" WordPress plugin, formerly…

2 days ago