In Moodle before 3.8.2, 3.7.5, 3.6.9 and 3.5.11, X-Forwarded-For headers could be used to spoof a user's IP, in order to bypass remote address checks.

Moodle exposed the names of hidden groups to users

Moodle reflected Cross-site Scripting (XSS)

Directory traversal vulnerability in repository/filesystem/lib.php in Moodle through 2.2.11, 2.3.x before 2.3.10, 2.4.x before 2.4.7, and 2.5.x before 2.5.3 allows remote authenticated users to read arbitrary files via a .. (dot dot) in a path.

Directory traversal vulnerability in file.php in Moodle 1.4.2 and earlier allows remote attackers to read arbitrary session files for known session IDs via a .. (dot dot) in the file parameter.

Moodle Authentication Bypass in Question-Bank

Cross-site request forgery (CSRF) vulnerability in the forum code in Moodle 1.7 before 1.7.7, 1.8 before 1.8.8, and 1.9 before 1.9.4 allows remote attackers to delete unauthorized forum posts via a link or IMG tag to post.php.

Cross-site scripting (XSS) vulnerability in admin/webservice/forms.php in the web services implementation in Moodle 2.0.x before 2.0.9, 2.1.x before 2.1.6, and 2.2.x before 2.2.3 allows remote authenticated users to inject arbitrary web script or HTML via the name field (aka the service name) to admin/webservice/service.php.

Cross site scripting in moodle

Moodle does not recogniz configuration setting that makes e-mail addresses visible only to course members

repository/repository_ajax.php in Moodle 2.2.x before 2.2.5 and 2.3.x before 2.3.2 allows remote authenticated users to bypass intended upload-size restrictions via a -1 value in the maxbytes field.

Moodle remote code execution via quiz questions

Unknown "front page vulnerability with Moodle servers" for Moodle before 1.3.2 has unknown impact and attack vectors.

Multiple cross-site scripting (XSS) vulnerabilities in lib/weblib.php in Moodle 1.9.x before 1.9.12 allow remote attackers to inject arbitrary web script or HTML via vectors related to URL encoding.

Moodle Cross-Site Request Forgery (CSRF)

Moodle Cross-site Scripting vulnerability in the KSES text cleaning filter

Moodle Stored HTML in assignment submission comments allowed links to be opened directly

Multiple cross-site scripting (XSS) vulnerabilities in lib/conditionlib.php in Moodle 2.4.x before 2.4.5 and 2.5.x before 2.5.1 allow remote attackers to inject arbitrary web script or HTML via the conditional access rule value of a user field.

PHPMailer vulnerable to email header injection

Multiple SQL injection vulnerabilities in the get_record function in datalib.php in Moodle 1.5.2 allow remote attackers to execute arbitrary SQL commands via the id parameter in (1) category.php and (2) info.php.