CVE-2021-27902 Craft CMS Cross-site Scripting Vulnerability
An XSS vulnerability in Craft CMS front-end forms allows attackers to inject malicious scripts via user uploads.
- 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-2021-27902?
CVE-2021-27902 is a medium-severity cross-site scripting vulnerability in Craftcms Craft Cms, published on 30 Jun 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
An issue was discovered in Craft CMS before 3.6.0. In some circumstances, a potential XSS vulnerability existed in connection with front-end forms that accepted user uploads.
Weakness: CWE-79
Which versions are affected by CVE-2021-27902?
2 open source packages ship an affected version, including craftcms/cms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
craftcms/cms Packagist | All versions | 3.6.0 |
craftcms/cms Packagist | All versions | 3.6.0 |
Products include Craftcms Craft Cms.
How do I fix CVE-2021-27902?
Upgrade craftcms/cms to 3.6.0 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-2021-27902 being exploited?
There is no known exploitation of CVE-2021-27902 in the wild and no public exploit code.
Other vulnerabilities in Craftcms Craft Cms
Sources
Also known as GHSA-3jxh-789f-p7m6.