CVE-2020-4049 Authenticated self-XSS via theme uploads in WordPress
Authenticated administrators can trigger JavaScript execution via crafted theme folder names during upload, requiring an upgrade to patched versions.
- 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
- Available
What is CVE-2020-4049?
CVE-2020-4049 is a low-severity cross-site scripting vulnerability in Debian Debian Linux, published on 12 Jun 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
In affected versions of WordPress, when uploading themes, the name of the theme folder can be crafted in a way that could lead to JavaScript execution in /wp-admin on the themes page. This does require an admin to upload the theme, and is low severity self-XSS. This has been patched in version 5.4.2, along with all the previously affected versions via a minor release (5.3.4, 5.2.7, 5.1.6, 5.0.10, 4.9.15, 4.8.14, 4.7.18, 4.6.19, 4.5.22, 4.4.23, 4.3.24, 4.2.28, 4.1.31, 4.0.31, 3.9.32, 3.8.34, 3.7.34).
Which versions are affected by CVE-2020-4049?
2 open source packages ship an affected version, including wordpress and wordpress-multisite. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
wordpress Bitnami | From 3.7.0 | 3.7.34, 3.8.34, 3.9.32, 4.0.31, 4.1.31, 4.2.28, 4.3.24, 4.4.23, 4.5.22, 4.6.19, 4.7.18, 4.8.14, 4.9.15, 5.0.10, 5.1.6, 5.2.7, 5.3.4, 5.4.2 |
wordpress-multisite Bitnami | From 3.7.0 | 3.7.34, 3.8.34, 3.9.32, 4.0.31, 4.1.31, 4.2.28, 4.3.24, 4.4.23, 4.5.22, 4.6.19, 4.7.18, 4.8.14, 4.9.15, 5.0.10, 5.1.6, 5.2.7, 5.3.4, 5.4.2 |
Products include Debian Debian Linux, Fedoraproject Fedora, Wordpress Wordpress.
How do I fix CVE-2020-4049?
Upgrade wordpress to a fixed version for your release line: 3.7.34, 3.8.34, 3.9.32 or 4.0.31.
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-2020-4049 being exploited?
There is no known exploitation of CVE-2020-4049 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BIT-wordpress-2020-4049, BIT-wordpress-multisite-2020-4049, DEBIAN-CVE-2020-4049, GHSA-87h4-phjv-rm6p, UBUNTU-CVE-2020-4049.