node/utils/ExportEtherpad.js in Etherpad 1.5.x before 1.5.2 might allow remote attackers to obtain sensitive information by leveraging an improper substring check when exporting a padID.
https://github.com/ether/etherpad-lite/releases/tag/1.5.2
https://github.com/ether/etherpad-lite/commit/a0fb65205c7d7ff95f00eb9fd88e93b300f30c3d