CVE-2021-43818

There's a flaw in python-lxml's HTML Cleaner component, which is responsible for sanitizing HTML and Javascript. An attacker who is able to submit a crafted payload to a web service using python-lxml's HTML Cleaner may be able to trigger script execution in clients such as web browsers. This can occur because the HTML Cleaner did not remove scripts within SVG images in data URLs such as <img src="">. XSS can result in impacts to the integrity and availability of the web page, as well as a potential impact to data confidentiality in some circumstances.

This flaw is rated as Moderate because code execution is limited to the web browser scope.

Following products ship affected component, however the vulnerability is not exposed in the product code. Therefore, we are reducing their impact to moderate.

• Red Hat Satellite 6.10
• Red Hat Update Infrastructure for Cloud Providers 4

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.