Serendipity before 2.3.4 on Windows allows remote attackers to execute arbitrary code because the filename of a renamed file may end with a dot. This file may then be renamed to have a .php filename.
Serendipity before 2.1.5 has XSS via EXIF data that is mishandled in the templates/2k11/admin/media_choose.tpl Editor Preview feature or the templates/2k11/admin/media_items.tpl Media Library feature.
SQL injection vulnerability in include/functions_entries.inc.php in Serendipity 2.0.5 allows remote authenticated users to execute arbitrary SQL commands via the cat parameter.
Open redirect vulnerability in comment.php in Serendipity through 2.0.5 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a URL in the HTTP Referer header.
include/functions_installer.inc.php in Serendipity through 2.0.5 is vulnerable to File Inclusion and a possible Code Execution attack during a first-time installation because it fails to sanitize the dbType POST parameter before adding it to an include() call in the bundled-libs/serendipity_generateFTPChecksums.php file.