CVE-2023-28439

Publication date

2023-03-22 20:55:00

Family

GitHub_M

State

PUBLISHED

Description

CKEditor4 is an open source what-you-see-is-what-you-get HTML editor. A cross-site scripting vulnerability has been discovered affecting Iframe Dialog and Media Embed packages. The vulnerability may trigger a JavaScript code after fulfilling special conditions: using one of the affected packages on a web page with missing proper Content Security Policy configuration; initializing the editor on an element and using an element other than `` as a base; and destroying the editor instance. This vulnerability might affect a small percentage of integrators that depend on dynamic editor initialization/destroy mechanism. A fix is available in CKEditor4 version 4.21.0. In some rare cases, a security fix may be considered a breaking change. Starting from version 4.21.0, the Iframe Dialog plugin applies the `sandbox` attribute by default, which restricts JavaScript code execution in the iframe element. To change this behavior, configure the `config.iframe_attributes` option. Also starting from version 4.21.0, the Media Embed plugin regenerates the entire content of the embed widget by default. To change this behavior, configure the `config.embed_keepOriginalContent` option. Those who choose to enable either of the more permissive options or who cannot upgrade to a patched version should properly configure Content Security Policy to avoid any potential security issues that may arise from embedding iframe elements on their web page.</p> </div> </div> </div> </div> </div> </div> </div> <footer> <div class="container py-4 py-lg-10"> <hr> <div class="text-muted d-flex justify-content-between align-items-center pt-3" style="text-align: center;"> <p class="mb-10"><center>Copyright © 2026 eXtreme Hosting</center></p> <p class="mb-10"><center><a href="/gdpr/">Privacy Policy GDPR/AVG</a> | <a href="/algemene-voorwaarden/">Algemene voorwaarden</a></center></p> </div> </div> </footer> <script src="/template/assets/bootstrap/js/bootstrap.min.js"></script> <script src="/template/assets/js/startup-modern.js"></script> </body> </html><img style="display: none;" src="https://telemetry.extremehosting.nl/Analy/?api=0C44A78F-C43E-4700-990A-0F40CE4B4A51&dtt=1746954019&urr=https://extremehosting.nl/cve/cve-details/CVE-2023-28439" />