SQL injection vulnerability in include/functions_trackbacks.inc.php in Serendipity 1.6.2 allows remote attackers to execute arbitrary SQL commands via the url parameter to comment.php.
Serendipity 1.5.5 allows remote attackers to obtain sensitive information via a direct request to a .php file, which reveals the installation path in an error message, as demonstrated by templates/newspaper/layout.php and certain other files.