Advanced Content Filter (ACF) vulnerability allowing to execute JavaScript code using malformed HTML

Affected packages

The vulnerability has been discovered in the Advanced Content Filter (ACF) module and may affect all plugins used by CKEditor 4.

Impact

A potential vulnerability has been discovered in CKEditor 4 Advanced Content Filter (ACF) core module. The vulnerability allowed to inject malformed HTML bypassing content sanitization, which could result in executing JavaScript code. It affects all users using the CKEditor 4 at version < 4.17.0.

Patches

The problem has been recognized and patched. The fix will be available in version 4.17.0.

For more information

Email us at [email protected] if you have any questions or comments about this advisory.

Acknowledgements

The CKEditor 4 team would like to thank Maurice Dauer (laytonctf) for recognizing and reporting this vulnerability.