WP-Stats WordPress Plugin contains a flaw that may allow an attacker to carry out an SQL injection attack. The issue is due to the wp-stats.php script not properly sanitizing user-supplied input to the 'author' variable. This may allow an attacker to inject or manipulate SQL queries in the back-end database.
Upgrade to version 2.01 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.