Oracle Linux: CVE-2024-22195: ELSA-2024-2348: python-jinja2 security update (MODERATE) (Multiple Advisories)

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.
A cross-site scripting (XSS) flaw was found in Jinja2 due to the xmlattr filter allowing keys with spaces, contrary to XML/HTML attribute standards. If an application accepts user-input keys and renders them for other users, attackers can inject additional attributes, potentially leading to XSS. This misuse of the xmlattr filter enables the injection of arbitrary HTML attributes, bypassing auto-escaping and potentially circumventing attribute validation checks.