The LTI (aka IMS-LTI) mod_form implementation in Moodle through 2.1.10, 2.2.x before 2.2.11, 2.3.x before 2.3.8, 2.4.x before 2.4.5, and 2.5.x before 2.5.1 does not properly support the sendname, sendemailaddr, and acceptgrades settings, which allows remote attackers to obtain sensitive information in opportunistic circumstances by leveraging an environment in which there was an ineffective attempt to enable the more secure values.