sshd in OpenSSH before 7.3, when SHA256 or SHA512 are used for user password hashing, uses BLOWFISH hashing on a static password when the username does not exist, which allows remote attackers to enumerate users by leveraging the timing difference between responses when a large password is provided.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-6210
Reference (s):
- BID:91812
- URL: http://www.securityfocus.com/bid/91812
- https://security.netapp.com/advisory/ntap-20190206-0001/
- https://www.openssh.com/txt/release-7.3
- DEBIAN:DSA-3626