from Hacker News

How to Bypass 2FA with an HTTP Header

by agrinman on 4/29/19, 9:00 PM with 4 comments

  • by lucb1e on 4/29/19, 9:35 PM

    Summary: 2FA token was only some digits, so can be brute forced. But they implemented rate limiting, based on IP. Unfortunately the application accepted the X-Forwarded-For header as if it were the real IP and by randomizing that header, you can do as many requests as you want.
  • by jonnismash on 4/29/19, 9:57 PM

    Misleading title, a better title would be: How I bypassed 2FA Rate-limits with an HTTP Header.