Package Instance

Cross-site Scripting
ckeditor is an open source WYSIWYG HTML editor with rich content support. A vulnerability has been discovered in the clipboard Widget plugin if used alongside the undo feature. The vulnerability allows a user to abuse undo functionality using malformed widget HTML, which could result in executing JavaScript code. It affects all users using the CKEditor 4 plugins listed above at The problem has been recognized and patched. The fix will be available

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CKEditor4 is an open source WYSIWYG HTML editor. The vulnerability allowed to inject malformed comments HTML bypassing content sanitization, which could result in executing JavaScript code. It affects all users using the CKEditor 4 at The problem has been recognized and patched.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CKEditor4 is an open source WYSIWYG HTML editor. The vulnerability allowed to inject malformed HTML bypassing content sanitization, which could result in executing JavaScript code.

CKEditor 4 ReDoS Vulnerability
It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).

CKEditor4 Cross-site Scripting vulnerability caused by incorrect CDATA detection
### Affected packages
The vulnerability has been discovered in the core HTML parsing module and may affect all editor instances that:
* Enabled [full-page editing](https://ckeditor.com/docs/ckeditor4/latest/features/fullpage.html) mode,
* or enabled [CDATA](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_dtd.html#property-S-cdata) elements in [Advanced Content Filtering](https://ckeditor.com/docs/ckeditor4/latest/guide/dev_advanced_content_filter.html) configuration (defaults to `script` and `style` elements).

### Impact

A potential vulnerability has been discovered in CKEditor 4 HTML processing core module. The vulnerability allowed to inject malformed HTML content bypassing Advanced Content Filtering mechanism, which could result in executing JavaScript code. An attacker could abuse faulty CDATA content detection and use it to prepare an intentional attack on the editor. It affects all users using the CKEditor 4 at version < 4.24.0-lts.

### Patches
The problem has been recognized and patched. The fix will be available in version 4.24.0-lts.

### For more information
Email us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.

### Acknowledgements
The CKEditor 4 team would like to thank [Michal Frýba](https://cz.linkedin.com/in/michal-fryba) from [ALEF NULA](https://www.alefnula.com/) for recognizing and reporting this vulnerability.

Inclusion of Functionality from Untrusted Control Sphere in CKEditor 4
It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted URL-like text into the editor, and then press Enter or Space (in the Autolink plugin).

CKEditor cross-site scripting vulnerability in AJAX sample
### Affected packages
The vulnerability has been discovered in the AJAX sample available at the `samples/old/ajax.html` file location. All integrators that use that sample in the production code can be affected.

### Impact

A potential vulnerability has been discovered in one of CKEditor's 4 samples that are shipped with production code. The vulnerability allowed to execute JavaScript code by abusing the AJAX sample. It affects all users using the CKEditor 4 at version < 4.24.0-lts where `samples/old/ajax.html` is used in a production environment.

### Patches
The problem has been recognized and patched. The fix will be available in version 4.24.0-lts.

### For more information
Email us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.

### Acknowledgements
The CKEditor 4 team would like to thank Rafael Pedrero and INCIBE ([original report](https://www.incibe.es/en/incibe-cert/notices/aviso/cross-site-scripting-vulnerability-cksource-ckeditor)) for recognizing and reporting this vulnerability.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
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 `<textarea>` 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.

CKEditor 4.0 vulnerability in the HTML Data Processor
A cross-site scripting (XSS) vulnerability in the HTML Data Processor for CKEditor 4.0 before 4.14.0 allows remote attackers to inject arbitrary web script through a crafted "protected" comment (with the cke_protected syntax).