Meta awarded researcher a $27,200 bug bounty for glitch that bypassed Facebook 2FA
Cover your face: Meta not too long ago carried out a centralized login system to make it simpler for Instagram, Facebook and Meta (VR) customers to handle their accounts. Unfortunately, when establishing a 2FA system, engineers ignored a evident failure relating to the restrict of makes an attempt.
A budding safety researcher named Gtm Mänôz seen the vulnerability in July 2022. While in search of his first bug bounty to current at BountyCon 2022, Mänôz began experimenting with the Meta Accounts Center interface, which manages all Meta accounts, and added a Google-like function—stopping logins to its varied providers (YouTube , Gmail, Docs, and so on.).
He famous that the web page permits customers to affiliate a telephone quantity with their account when linked. Users merely enter their telephone quantity, adopted by a six-digit 2FA code despatched to them by the system. However, Mänôz discovered that if an incorrect code was entered, Account Center merely requested the consumer to re-enter it, reasonably than sending a brand new code.
Also, there isn’t a restrict to the variety of failed makes an attempt inside the validation field. This oversight allowed Mänôz to brute drive 2FA on his personal account, linking his telephone quantity to a different Facebook profile. The solely caveat got here after Meta despatched victims their telephone quantity stolen in an e mail informing them that the quantity had been linked to a different consumer’s account.
While the harm of this bug is usually restricted to the trouble of re-establishing the proprietor’s telephone quantity, it successfully disables 2FA for the sufferer’s account, albeit briefly. Before the goal takes motion, they’re weak to password phishing assaults.
“Basically, the largest influence right here is to revoke SMS-based 2FA for anybody who is aware of the telephone quantity,” Mänôz advised TechCrunch.
Mänôz notified Meta of the bug in September, and the vulnerability was instantly patched. When Mänôz found the issue, Meta Accounts Center was nonetheless in beta and solely accessible to a small variety of customers, a spokesperson mentioned. The consultant additionally famous that Meta’s survey confirmed no spike in utilization of the function, suggesting hackers weren’t profiting from it.
Despite the comparatively low dealing with of the bug, Meta awarded Mänôz a $27,200 bug bounty. Not dangerous for his first bug looking.
Over the previous few years, Meta has stumbled in the case of login performance for its varied accounts. In 2021, it brought on a gentle panic when it reconfigured the location to log everybody out of Facebook. Last 12 months, it intentionally locked many customers out of their accounts as a result of they did not allow “Facebook Protect” by the deadline set by the official Meta e mail, in what gave the impression to be a phishing rip-off.