CVE-2021-20186: XSS

Published Jan 28, 2021
·
Updated

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.

Affected Software

8 affected componentsFixes available
composer/moodle/moodle>=3.5<3.5.16
3.5.16
composer/moodle/moodle>=3.8<3.8.7
3.8.7
composer/moodle/moodle>=3.9<3.9.4
3.9.4
composer/moodle/moodle>=3.10<3.10.1
3.10.1
Moodle moodle<3.5.16
Moodle moodle>=3.8.0<3.8.7
Moodle moodle>=3.9.0<3.9.4
Moodle moodle>=3.10.0<3.10.1

Event History

Jan 28, 2021
CVE Published
via MITRE·06:38 PM
Data Sourced
via MITRE·06:38 PM
DescriptionWeakness
May 24, 2022
Advisory Published
via GitHub·05:40 PM

Frequently Asked Questions

1

What is the severity of CVE-2021-20186?

CVE-2021-20186 has a medium severity rating due to the risk of stored XSS when the TeX notation filter is enabled.

2

How do I fix CVE-2021-20186?

To fix CVE-2021-20186, upgrade your Moodle installation to versions 3.10.1, 3.9.4, 3.8.7, or 3.5.16 or later.

3

Which software versions are affected by CVE-2021-20186?

CVE-2021-20186 affects Moodle versions prior to 3.10.1, 3.9.4, 3.8.7, and 3.5.16.

4

What type of vulnerability is CVE-2021-20186?

CVE-2021-20186 is categorized as a Cross-Site Scripting (XSS) vulnerability.

5

Can CVE-2021-20186 be exploited remotely?

Yes, CVE-2021-20186 can potentially be exploited remotely if the TeX notation filter is enabled.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203