The hacker discovered that if you place several withdrawals all in practically the same instant, they will get processed at more or less the same time. This will result in a negative balance, but valid insertions into the database, which then get picked up by the withdrawal daemon.
When I was a kid I imagined that banks were incredibly vulnerable to this.
Later I discovered transactions and thought my kid-self was just silly.
I've learned that my kid-self understood things pretty well, sometimes.
When I was a kid I imagined that banks were incredibly vulnerable to this.
Later I discovered transactions and thought my kid-self was just silly.
I've learned that my kid-self understood things pretty well, sometimes.