CVE-2021-36398 Moodle Cross-site Scripting vulnerability

Medium 5.4 Published Updated

Attackers can inject malicious scripts via unsanitized ID numbers in web service tokens, potentially leading to session hijacking or code execution.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2021-36398?

CVE-2021-36398 is a medium-severity cross-site scripting vulnerability in Moodle Moodle, published on 6 Mar 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

In moodle, ID numbers displayed in the web service token list required additional sanitizing to prevent a stored XSS risk.

Weakness: CWE-79

Which versions are affected by CVE-2021-36398?

3 open source packages ship an affected version, including moodle/moodle and moodle. It affects 1 product.

PackageAffectedFixed in
moodle/moodle PackagistFrom 3.113.11.1
moodle/moodle PackagistFrom 3.113.11.1
moodle BitnamiFrom 3.11.03.11.1

Products include Moodle Moodle.

How do I fix CVE-2021-36398?

Upgrade moodle/moodle to 3.11.1 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2021-36398 being exploited?

There is no known exploitation of CVE-2021-36398 in the wild and no public exploit code.

All Moodle Moodle vulnerabilities

Sources

Also known as BIT-moodle-2021-36398, GHSA-786g-xv8v-9h93, UBUNTU-CVE-2021-36398.

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