The default password hashing algorithm (PBKDF2-HMAC-SHA1) in Liferay Portal 7.2.0 up to and including 7.4.3.15, and older unsupported versions, and Liferay DXP 7.4 before update 16, 7.3 before update 4, 7.2 before fix pack 17, and older unsupported versions defaults to a low work factor, which allows malicious users to quickly crack password hashes.
Vulmon