The "File upload question" functionality in LimeSurvey 3.x-LTS through 3.27.18 allows XSS in assets/scripts/modaldialog.js and assets/scripts/uploader.js.
LimeSurvey 2.6.x before 2.6.7, 2.7x.x before 2.73.1, and 3.x before 3.4.2 mishandles application/controller/InstallerController.php after installation, which allows remote attackers to access the configuration file.