The remote host is vulnerable to an HTML injection attack.
The remote host is running pLog, a blog system implemented in PHP. It is reported that every version up to and including 0.3.2 are prone to an HTML injection issue in the user registration form. An attacker may use the 'username' and 'blog' fields to inject malicous HTML codes and scripts in web pages. The malicious code will be executed by a victim's browser when a tampered page is displayed. For example, the summary.php page that lists every user and their blog on the system.
No solution is known at this time.