I’m a Swiss voter living abroad, and like all Swiss expats from Basel-Stadt, St.Gallen or Thurgau, I’ve been invited to vote over the internet in this year’s national election. Switzerland’s e-voting system is supposed to have safeguards to protect the election against malicious actors, however as a computer scientist, I have found a flaw in the practical implementation of one of those safeguards.

n late November 2022, a few days after ETH Alumni launched their new feature “Who is who” which allows them to look up and connect to other members, I came across a severe access control vulnerability. Without any authorization over the internet, it allowed extracting at least 35418 member profiles, including full name, postal address, nationality, title, graduation field, study start year, gender, profile picture and hashed passwords.