Vulnerability · Published Dec 30, 2020 · Assigned by tenable

CVE-2020-5809

Medium 5.4

In plain English

A medium-severity security flaw in Umbraco CMS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities).

Severity (CVSS NVD)5.4Medium

Exploit odds (30 days)0.7%top 47.2% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

A stored XSS vulnerability exists in Umbraco CMS <= 8.9.1 or current. An authenticated user can inject arbitrary JavaScript code into iframes when editing content using the TinyMCE rich-text editor, as TinyMCE is configured to allow iframes by default in Umbraco CMS.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
NuGet	umbracocms.core	no fix listed	GHSA-95qr-67rx-9pgh

Affected products (as reported)

Vendor	Product	Versions
n/a	Umbraco CMS	<= 8.9.1 or current (unfixed)

References

https://www.tenable.com/security/research/tra-2020-59 x_refsource_MISC