It was found in Moodle before version 3.10.1, 3.9.4, 3.8.7 and 3.5.16 that if the TeX notation filter was enabled, additional sanitizing of TeX content was required to prevent the risk of stored XSS.

The version of Moodle installed on the remote host is 3.5.x prior to 3.5.16, 3.8.x prior to 3.8.7, 3.9.x prior to 3.9.4 or 3.10.x prior to 3.10.1. It is, therefore, affected by multiple vulnerabilities:

 - A client-side Denial of Service (DoS) attack due to the lack of character limit when sending messages. (CVE-2021-20185)

 - A stored Cross-Site Scripting vulnerability due to the lack of sanitization of TeX content when the TeX notation filter is enabled. (CVE-2021-20186)

 - An arbitrary PHP code execution by site administrators via a PHP include used during Shibboleth authentication. (CVE-2021-20187)

 - An information disclosure in grade related web services, allowing students to view other students grades. (CVE-2021-20184)

 - A Cross-Site Scripting (XSS) vulnerability due to the lack of input sanitization on the search template inputs. (CVE-2021-20183)

Note that the scanner has not attempted to exploit this issue but has instead relied only on application's self-reported version number.

ID	Name	Product	Family	Severity
113633	Moodle 3.10.x < 3.10.1 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	high
113632	Moodle 3.9.x < 3.9.4 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	high
113631	Moodle 3.8.x < 3.8.7 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	high
113630	Moodle 3.5.x < 3.5.16 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	high

Detections

Analytics

CVE-2021-20186

medium

Tenable Plugins

high

high

high

high