Improper Input Validation
An issue was discovered in Moodle versions before 3.1.11, 3.2.x before 3.2.9, 3.3.x before 3.3.6, 3.4.x before 3.4.2 and 3.5.0-beta. By substituting URLs in portfolios, users can instantiate any class. This can also be exploited by users who are logged in as guests to create a DDoS attack.
CWE-20 - Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.