An unauthorized party accessed Stack Overflow's production systems earlier this month and executed privileged web requests that exposed information on roughly 250 public network users, the Q&A website for programmers announced last Friday.
Stack Overflow Vice President of Engineering Mary Ferguson said in a May 17 blog post that the intruder exploited a bug in the development tier for stackoverflow.com, allowing the individual to log in as of May 5, 2019. The breach went unnoticed until May 11, when the perpetrator was detected after escalating his (or her) access on the website's production version. Shortly thereafter, Stack Overflow revoked the intruder's privileges and commenced an investigation.
During the time he had privileged access, the unauthorized party executed several privileged web requests that potentially returned data on roughly 250 public network users of Stack Exchange, a network of Q&A websites that operates Stack Overflow. Affected data included IP addresses, names and emails. Ferguson said that the website team would be reaching out to impacted users.
According to Ferguson, the website team has also been taking action by auditing logs and databases; fixing the original bug and other attack vectors found during the investigation; engaging a third-party forensics and incident response firm; and "taking precautionary measures such as cycling secrets, resetting company passwords and evaluating systems and security levels."