CVE-2021-4020 Cross-site Scripting (XSS) - Stored in meetecho/janus-gateway

High 8.8 Published 27 Nov 2021 Updated 3 Aug 2024

Stored XSS in Janus Gateway allows attackers to inject malicious scripts, potentially leading to session hijacking or data theft.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2021-4020?

CVE-2021-4020 is a high-severity cross-site scripting vulnerability in meetecho/janus-gateway, published on 27 Nov 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

janus-gateway is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Weakness: CWE-79

Which versions are affected by CVE-2021-4020?

It affects 1 product.

Products include Meetecho Janus.

How do I fix CVE-2021-4020?

Apply the vendor's patch.

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-2021-4020 being exploited?

There is no known exploitation of CVE-2021-4020 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2021-4020, GHSA-cq47-8w25-m65v, UBUNTU-CVE-2021-4020, openSUSE-SU-2024:11675-1.