Both the Sun Java System Access Manager and Identity Manager suffer from a user enumeration vulnerability. Identity Manager versions 7.0, 7.1, 7.1.1, and 8.0 are affected. Access Manager versions 6 2005Q1 (6.3), 7 2005Q4 (7.0), and 7.1 are affected.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/76403/sunjava-enumerate.txt
Source: https://packetstormsecurity.com/files/76403/Sun-Java-Users-Enumeration.html