Cross-site scripting (XSS) vulnerability in the process function in SSViewer.php in SilverStripe before 2.3.13 and 2.4.x before 2.4.6 allows remote attackers to inject arbitrary web script or HTML via the QUERY_STRING to template placeholders, as demonstrated by a request to (1) admin/reports/, (2) admin/comments/, (3) admin/, (4) admin/show/, (5) admin/assets/, and (6) admin/security/.

SilverStripe 2.3.x before 2.3.12 and 2.4.x before 2.4.6 allows remote authenticated users with the EDIT_PERMISSIONS permission to gain administrator privileges via a TreeMultiselectField that includes admin groups when adding a user to the selected groups.

code/sitefeatures/PageCommentInterface.php in SilverStripe 2.4.x before 2.4.6 might allow remote attackers to execute arbitrary code via a crafted cookie in a user comment submission, which is not properly handled when it is deserialized.

SQL injection vulnerability in the addslashes method in SilverStripe 2.3.x before 2.3.12 and 2.4.x before 2.4.6, when connected to a MySQL database using far east character encodings, allows remote attackers to execute arbitrary SQL commands via unspecified vectors.