CVE-2019-17022

high-risk
Published 2020-01-08

When pasting a &lt;style&gt; tag from the clipboard into a rich text editor, the CSS sanitizer does not escape &lt; and &gt; characters. Because the resulting string is pasted directly into the text node of the element this does not result in a direct injection into the webpage; however, if a webpage subsequently copies the node's innerHTML, assigning it to another innerHTML, this would result in an XSS vulnerability. Two WYSIWYG editors were identified with this behavior, more may exist. This vulnerability affects Firefox ESR < 68.4 and Firefox < 72.

Do I need to act?

~
4.6% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
6
CVSS 6.1/10 Medium
NETWORK / LOW complexity

Affected Vendors

50
/ 100
high-risk
Severity 23/34 · High
Exploitability 8/34 · Low
Exposure 19/34 · Moderate