hdchinh

hi, i'm daniel. i'm a 15-year-old high school junior. in my free time, i hack billion dollar companies and build cool stuff.

3 months ago, I discovered a unique 0-click deanonymization attack that allows an attacker to grab the location of any target within a 250 mile radius. With a vulnerable app installed on a target's phone (or as a background application on their laptop), an attacker can send a malicious payload and deanonymize you within seconds--and you wouldn't even know.

I'm publishing this writeup and research as a warning, especially for journalists, activists, and hackers, about this type of undetectable attack. Hundreds of applications are vulnerable, including some of the most popular apps in the world: Signal, Discord, Twitter/X, and others. Here's how it works:

Cloudflare

By the numbers, Cloudflare is easily the most popular CDN on the market. It beats out competitors such as Sucuri, Amazon CloudFront, Akamai, and Fastly. In 2019, a major Cloudflare outage k

hdchinh

require "prawn"

class AddWatermarkService
  def initialize(cv)
    @cv = cv
  end

  def perform
    begin
      return { cv: @cv, success: false } if File.extname(@cv.original_filename) != ".pdf"

hdchinh

1. Gemfile

gem 'ckeditor', github: 'galetahub/ckeditor'

2. bundle install

3. app/assets/javascripts/application.js
//= require ckeditor/init

4. config/initializers/active_admin.rb

hdchinh

Requirements

Run pip install pipenv to install pipenv

Run pipenv shell to create an environment, if does not exist, and activate it.

Run pipenv install python_decouple whitenoise dj_database_url Pillow gunicorn May take a while.

This should create two files: Pipfile and Pipfile.lock. Keep them in the project root.

hdchinh

class AppleSignInController < ApplicationController
  APPLE_PEM_URL = "https://appleid.apple.com/auth/keys"

  # /api/apple/validate
  def validate

    name = params[:name]
    userIdentity = params[:userIdentity]
    jwt = params[:jwt]

hdchinh

Translated from https://blog.isquaredsoftware.com/2020/05/blogged-answers-a-mostly-complete-guide-to-react-rendering-behavior/, author: Mark Erikson (from Redux team)

A (Mostly) Complete Guide to React Rendering Behavior

Bài viết cung cấp chi tiết về cách mà React render hoạt động, và việc sử dụng Context và Redux ảnh hưởng thế nào tới quá trình render của React.

"Render" là gì

Rendering is the process of React asking your components to describe what they want their section of the UI to look like, now, based on the current combination of props and state.

hdchinh

 ["Africa/Algiers", "West Central Africa"],
 ["Africa/Cairo", "Cairo"],
 ["Africa/Casablanca", "Casablanca"],
 ["Africa/Harare", "Harare"],
 ["Africa/Johannesburg", "Pretoria"],
 ["Africa/Monrovia", "Monrovia"],
 ["Africa/Nairobi", "Nairobi"],
 ["America/Argentina/Buenos_Aires", "Buenos Aires"],
 ["America/Bogota", "Bogota"],
 ["America/Caracas", "Caracas"],

hdchinh

t = 236 # seconds
Time.at(t).utc.strftime("%H:%M:%S")
=> "00:03:56"

# Reference
# http://stackoverflow.com/questions/3963930/ruby-rails-how-to-convert-seconds-to-time

hdchinh

1. Form
2. Router

hdchinh

import React from 'react';

class App extends React.Component {
  handleClick = (e, data) => {
    console.log(data);
  }

  render() {
    const data = 10;
    const data2 = 20;