Package Instance

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.

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.

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 vulnerability has been discovered in the core HTML processing module and may affect all plugins used by CKEditor 4 prior to version 4.18.0. The vulnerability allows someone to inject malformed HTML bypassing content sanitization, which could result in executing JavaScript code. This problem has been patched in version 4.18.0. There are currently no known workarounds.

Code Snippet GeSHi plugin in CKEditor 4 has reflected cross-site scripting (XSS) vulnerability
### Affected packages
The vulnerability has been discovered in [Code Snippet GeSHi](https://ckeditor.com/cke4/addon/codesnippetgeshi) plugin. All integrators that use [GeSHi syntax highlighter](https://github.com/GeSHi/geshi-1.0) on the backend side can be affected.

### Impact
A potential vulnerability has been discovered in CKEditor 4 [Code Snippet GeSHi](https://ckeditor.com/cke4/addon/codesnippetgeshi) plugin. The vulnerability allowed a reflected XSS attack by exploiting a flaw in the [GeSHi syntax highlighter library](https://github.com/GeSHi/geshi-1.0) hosted by the victim.

The GeSHi library was included as a vendor dependency in CKEditor 4 source files. In a specific scenario, an attacker could craft a malicious script that could be executed by sending a request to the GeSHi library hosted on a PHP web server.

### Patches

The [GeSHi library](https://github.com/GeSHi/geshi-1.0) is no longer actively maintained. Due to the lack of ongoing support and updates, potential security vulnerabilities have been identified with its continued use. To mitigate these risks and enhance the overall security of the CKEditor 4, we have decided to completely remove the GeSHi library as a dependency. This change aims to maintain a secure environment and reduce the risk of any security incidents related to outdated or unsupported software.

To integrators who still want to use the GeSHi syntax highlighter, we recommend manually adding the [GeSHi library](https://github.com/GeSHi/geshi-1.0) . Please be aware of and understand the potential security vulnerabilities associated with its use.

The fix is be available in version 4.25.0-lts.

### Acknowledgements

The CKEditor 4 team would like to thank [Jiasheng He](https://github.com/Hebing123) from Qihoo 360 for recognizing and reporting this vulnerability.

### For more information

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

CKEditor4 Cross-site Scripting vulnerability in samples with enabled the preview feature
### Affected packages
The vulnerability has been discovered in the samples that use the [preview](https://ckeditor.com/cke4/addon/preview) feature:

* `samples/old/**/*.html`
* `plugins/[plugin name]/samples/**/*.html`

All integrators that use these samples 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 misconfigured [preview feature](https://ckeditor.com/cke4/addon/preview). It affects all users using the CKEditor 4 at version < 4.24.0-lts with affected samples 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 [Marcin Wyczechowski](https://www.linkedin.com/in/marcin-wyczechowski-0a823795/) & [Michał Majchrowicz](https://www.linkedin.com/in/micha%C5%82-majchrowicz-mwsc/) [AFINE Team](https://afine.com/) for recognizing and reporting this vulnerability.

Improper Input Validation
CKEditor4 is an open source what-you-see-is-what-you-get HTML editor. CKEditor4 prior to version 4.18.0 contains a vulnerability in the `dialog` plugin. The vulnerability allows abuse of a dialog input validator regular expression, which can cause a significant performance drop resulting in a browser tab freeze. A patch is available in version 4.18.0. There are currently no known workarounds.

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.