CVE-2020-35124 XSS vulnerability leveraged through referrers could allow un-authorized admin access in Mautic

Critical 9.6 Published 28 Jan 2021 Updated 4 Aug 2024

Remote attackers can inject executable JavaScript via the Referer header in Mautic asset downloads, potentially compromising user sessions.

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

What is CVE-2020-35124?

CVE-2020-35124 is a critical cross-site scripting vulnerability in n/a, published on 28 Jan 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A cross-site scripting (XSS) vulnerability in the assets component of Mautic before 3.2.4 allows remote attackers to inject executable JavaScript through the Referer header of asset downloads.

Weakness: CWE-79

Which versions are affected by CVE-2020-35124?

4 open source packages ship an affected version, including mautic/core. It affects 1 product.

Package	Affected	Fixed in
`mautic/core` Packagist	From `2.0.0`	`2.16.5`
`mautic/core` Packagist	From `2.0.0`	`2.16.5`
`mautic/core` Packagist	From `3.0.0`	`3.2.4`
`mautic/core` Packagist	From `3.0.0`	`3.2.4`

Products include Acquia Mautic.

How do I fix CVE-2020-35124?

Upgrade mautic/core to a fixed version for your release line: 2.16.5 or 3.2.4.

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-2020-35124 being exploited?

There is no known exploitation of CVE-2020-35124 in the wild and no public exploit code.

Sources

Also known as GHSA-39wj-j3jc-858m.