classes/GoogleSpell.php in the PHP Spellchecker (aka Google Spellchecker) addon before 2.0.6.1 for TinyMCE, as used in Moodle 2.1.x before 2.1.10, 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 and other products, does not properly handle control characters, which allows remote attackers to trigger arbitrary outbound HTTP requests via a crafted string.
grade/edit/outcome/edit_form.php in Moodle 1.9.x through 1.9.19, 2.1.x before 2.1.10, 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 does not properly enforce the moodle/grade:manage capability requirement, which allows remote authenticated users to convert custom outcomes into standard site-wide outcomes by leveraging the teacher role and using the re-editing feature.
The moodle1 backup converter in backup/converter/moodle1/lib.php in Moodle 2.1.x before 2.1.10, 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 does not properly validate pathnames, which allows remote authenticated users to read arbitrary files by leveraging the backup-restoration feature.
report/outline/index.php in Moodle 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 does not properly enforce the moodle/user:viewhiddendetails capability requirement, which allows remote authenticated users to discover a hidden lastaccess value by reading an activity report.
Multiple open redirect vulnerabilities in Moodle 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 allow remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via vectors related to (1) backup/backupfilesedit.php, (2) comment/comment_post.php, (3) course/switchrole.php, (4) mod/wiki/filesedit.php, (5) tag/coursetags_add.php, or (6) user/files.php.
Multiple cross-site request forgery (CSRF) vulnerabilities in user/messageselect.php in the messaging system in Moodle 2.2.x before 2.2.7, 2.3.x before 2.3.4, and 2.4.x before 2.4.1 allow remote attackers to hijack the authentication of arbitrary users for requests that send course messages.
The Database activity module in Moodle 2.1.x before 2.1.9, 2.2.x before 2.2.6, and 2.3.x before 2.3.3 allows remote authenticated users to read activity entries of a different group's users via an advanced search.
The Portfolio plugin in Moodle 2.1.x before 2.1.9, 2.2.x before 2.2.6, and 2.3.x before 2.3.3 allows remote authenticated users to upload and execute files via a modified Portfolio API callback.
The Database activity module in Moodle 2.1.x before 2.1.9, 2.2.x before 2.2.6, and 2.3.x before 2.3.3 allows remote attackers to bypass intended restrictions on reading other participants' entries via an advanced search.
The Dropbox Repository File Picker in Moodle 2.1.x before 2.1.9, 2.2.x before 2.2.6, and 2.3.x before 2.3.3 allows remote authenticated users to access the Dropbox of a different user by leveraging an unattended workstation after a logout.