Kiwi TCMS Stored Cross-site Scripting via SVG file

Impact

Kiwi TCMS accepts SVG files uploaded by users which could potentially contain JavaScript code. If SVG images are viewed directly, i.e. not rendered in an HTML page, this JavaScript code could execute.

Patches

This vulnerability has been fixed by configuring Kiwi TCMS to serve with the Content-Security-Policy HTTP header which blocks inline JavaScript in all modern browsers.

Workarounds

Configure Content-Security-Policy header, see commit 6617cee0.

References

You can visit https://digi.ninja/blog/svg_xss.php for more technical details.

Independently disclosed by Antonio Spataro and @1d8.