Description It was possible to confirm a single character of a user's password hash (just the hash, not the password) using a specially crafted regular expression filter in the users endpoint of the REST API. Many requests could eventually uncover the entire hash. The hash would not be in the response, however the presence or absence of a result would confirm if the character was in the right position. It would take a long time since the API has throttling enabled by default. Additionally, the REST API would need to be enabled, as well as the users endpoint. Both of which are disabled by default. Resolution Filtering by password or password hash has been disabled. Credits We would like to thank Thibaud Kehler for reporting the…