ownCloud Exposure of Sensitive Information to an Unauthorized Actor Vulnerability - CVE-2017-5865
The password reset functionality in ownCloud Server before 8.1.11 8.2.x before 8.2.9 9.0.x before 9.0.7 and 9.1.x before 9.1.3 sends different error messages depending on whether the username is valid which allows remote attackers to enumerate user names via a large number of password reset attempts.