Package Instance

CKEditor4 low-risk cross-site scripting (XSS) vulnerability linked to potential domain takeover
### Affected Packages

The issue impacts only editor instances with enabled [version notifications](https://ckeditor.com/docs/ckeditor4/latest/api/CKEDITOR_config.html#cfg-versionCheck).

Please note that this feature is disabled by default in all CKEditor 4 LTS versions. Therefore, if you use CKEditor 4 LTS, it is highly unlikely that you are affected by this vulnerability. If you are unsure, please [contact us](mailto:security@cksource.com).

### Impact

A theoretical vulnerability has been identified in CKEditor 4.22 (and above). In a highly unlikely scenario where an attacker gains control over the https://cke4.ckeditor.com domain, they could potentially execute an attack on CKEditor 4 instances. Although the vulnerability is purely hypothetical, we have addressed it in CKEditor 4.25.0-lts to ensure compliance with security best practices.

### Patches

The issue has been recognized and patched. The fix is available in version 4.25.0-lts.

### For More Information

If you have any questions or comments about this advisory, please email us at [security@cksource.com](mailto:security@cksource.com).

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.

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.