CVE-2021-41836 Fathom Analytics <= 3.0.4 Authenticated Stored Cross-Site Scripting
Administrators can inject arbitrary web scripts via the site_id parameter in Fathom Analytics, affecting multi-site installations with specific HTML filtering settings.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-41836?
CVE-2021-41836 is a medium-severity cross-site scripting vulnerability in Fathom Analytics, published on 14 Dec 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
The Fathom Analytics WordPress plugin is vulnerable to Stored Cross-Site Scripting due to insufficient input validation and escaping via the $site_id parameter found in the ~/fathom-analytics.php file which allowed attackers with administrative user access to inject arbitrary web scripts, in versions up to and including 3.0.4. This affects multi-site installations where unfiltered_html is disabled for administrators, and sites where unfiltered_html is disabled.
Weakness: CWE-79
Which versions are affected by CVE-2021-41836?
It affects 1 product.
Products include Conva Fathom Analytics.
How do I fix CVE-2021-41836?
No fix has been published for CVE-2021-41836 yet. Limit exposure of the affected software until one is available.
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-2021-41836 being exploited?
There is no known exploitation of CVE-2021-41836 in the wild and no public exploit code.
Sources
Also known as GHSA-4rfr-wr94-r2xv.