The LTI module in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 does not properly restrict the parameters used in a return URL, which allows remote attackers to trigger the generation of arbitrary messages via a modified URL, related to mod/lti/locallib.php and mod/lti/return.php.

Cross-site scripting (XSS) vulnerability in group/overview.php in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 allows remote authenticated users to inject arbitrary web script or HTML via a modified grouping description.

lib/setup.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 does not provide charset information in HTTP headers, which might allow remote attackers to conduct cross-site scripting (XSS) attacks via UTF-7 characters during interaction with AJAX scripts.

tag/tag_autocomplete.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 does not consider the moodle/tag:edit capability before adding a tag, which allows remote authenticated users to bypass intended access restrictions via an AJAX request.

The generate_password function in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 does not provide a sufficient number of possible temporary passwords, which allows remote attackers to obtain access via a brute-force attack.

iplookup/index.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 allows remote attackers to cause a denial of service (resource consumption) by triggering the calculation of an estimated latitude and longitude for an IP address.

The grade-reporting feature in Singleview (aka Single View) in Moodle 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 does not consider the moodle/grade:manage capability, which allows remote authenticated users to modify "Exclude grade" settings by leveraging the Non-Editing Instructor role.

Multiple cross-site request forgery (CSRF) vulnerabilities in the Forum module in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 allow remote attackers to hijack the authentication of arbitrary users for requests that set a tracking preference within (1) mod/forum/deprecatedlib.php, (2) mod/forum/forum.js, (3) mod/forum/index.php, or (4) mod/forum/lib.php.

mod/wiki/admin.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 allows remote authenticated users to remove wiki pages by leveraging delete access within a different subwiki.

The core_enrol_get_enrolled_users web service in enrol/externallib.php in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 does not properly implement group-based access restrictions, which allows remote authenticated users to obtain sensitive course-participant information via a web-service request.

Multiple cross-site request forgery (CSRF) vulnerabilities in the LTI module in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 allow remote attackers to hijack the authentication of arbitrary users for a (1) mod/lti/request_tool.php or (2) mod/lti/instructor_edit_tool_type.php request.

webservice/upload.php in Moodle 2.6.x before 2.6.6 and 2.7.x before 2.7.3 does not ensure that a file upload is for a private or draft area, which allows remote authenticated users to upload files containing JavaScript, and consequently conduct cross-site scripting (XSS) attacks, by specifying the profile-picture area.

mod/forum/externallib.php in Moodle 2.6.x before 2.6.6 and 2.7.x before 2.7.3 does not verify group permissions, which allows remote authenticated users to access a forum via the forum_get_discussions web service.

The (1) core_enrol_get_course_enrolment_methods and (2) enrol_self_get_instance_info web services in Moodle through 2.6.11, 2.7.x before 2.7.12, 2.8.x before 2.8.10, 2.9.x before 2.9.4, and 3.0.x before 3.0.2 do not consider the moodle/course:viewhiddencourses capability, which allows remote authenticated users to obtain sensitive information via a web-service request.

mod/data/edit.php in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 sets a certain group ID to zero upon a database-entry change, which allows remote authenticated users to obtain sensitive information by accessing the database after an edit by a teacher.

mod/lti/launch.php in the LTI module in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 performs access control at the course level rather than at the activity level, which allows remote authenticated users to bypass the mod/lti:view capability requirement by viewing an activity instance.

lib/classes/grades_external.php in Moodle 2.7.x before 2.7.3 does not consider the moodle/grade:viewhidden capability before displaying hidden grades, which allows remote authenticated users to obtain sensitive information by leveraging the student role to access the get_grades web service.

Cross-site scripting (XSS) vulnerability in the advanced-search feature in mod_data in Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 allows remote attackers to inject arbitrary web script or HTML via a crafted field in a URL, as demonstrated by a search form field.

Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 does not properly restrict links, which allows remote attackers to obtain sensitive URL information by reading a Referer log.

Cross-site scripting (XSS) vulnerabilities in Moodle CMS on or before 3.1.2 allow remote attackers to inject arbitrary web script or HTML via the s_additionalhtmlhead, s_additionalhtmltopofbody, and s_additionalhtmlfooter parameters.