Google has stepped in to handle a security flaw that would have made it doable to brute-force an account’s restoration telephone quantity, probably exposing them to privateness and security dangers.
The problem, in line with Singaporean security researcher “brutecat,” leverages a difficulty within the firm’s account restoration function.
That stated, exploiting the vulnerability hinges on a number of shifting elements, particularly focusing on a now-deprecated JavaScript-disabled model of the Google username restoration type (“accounts.google[.]com/signin/usernamerecovery”) that lacked anti-abuse protections designed to forestall spammy requests.
The web page in query is designed to assist customers verify if a restoration e mail or telephone quantity is related to a selected show title (e.g., “John Smith”).

However circumventing the CAPTCHA-based charge restrict finally made it doable to check out all permutations of a Google account’s telephone quantity in a brief house of time and arrive on the right digits in seconds or minutes, relying on the size of the telephone quantity (which varies from nation to nation).
An attacker might additionally reap the benefits of Google’s Forgot Password stream to determine the nation code related to a sufferer’s telephone quantity, in addition to get hold of their show title by making a Looker Studio doc and transferring possession to the sufferer, successfully inflicting their full title to be leaked on the house web page.
In all, the exploit requires performing the next steps –
- Leak the Google account show title through Looker Studio
- Run the forgot password stream for a goal e mail tackle to get the masked telephone quantity with the final 2 digits exhibited to the attacker (e.g., •• ••••••03)
- Brute-force the telephone quantity in opposition to the username restoration endpoint to brute-force the telephone quantity
Brutecat stated a Singapore-based quantity may very well be leaked utilizing the aforementioned approach in a span of 5 seconds, whereas a U.S. quantity may very well be unmasked in about 20 minutes.
Armed with the data of a telephone quantity related to a Google account, a foul actor might take management of it by means of a SIM-swapping assault and finally reset the password of any account related to that telephone quantity.
Following accountable disclosure on April 14, 2025, Google awarded the researcher a $5,000 bug bounty and plugged the vulnerability by fully eliminating the non-JavaScript username restoration type as of June 6, 2025.
The findings come months after the identical researcher detailed one other $10,000 exploit that an attacker might have weaponized to reveal the e-mail tackle of any YouTube channel proprietor by chaining a flaw within the YouTube API and an outdated internet API related to Pixel Recorder.

Then in March, brutecat additionally revealed that it is doable to glean e mail addresses belonging to creators who’re a part of the YouTube Associate Program (YPP) by leveraging an entry management concern within the “/get_creator_channels” endpoint, incomes them a reward of $20,000.
“[An] entry management concern in /get_creator_channels leaks channel contentOwnerAssociation, which results in channel e mail tackle disclosure through Content material ID API,” Google stated.
“An attacker with entry to a Google account that had a channel that joined the YouTube Associate Program (over 3 million channels) can get hold of the e-mail tackle in addition to monetization particulars of some other channel within the YouTube Associate Program. The attacker can use this to de-anonymize a YouTuber (as there may be an expectation of pseudo-anonymity in YouTube), or phish them.”