Ckeditor 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. (2022-03-16, CVE-2022-24728)

CKEditor4 is an open source WYSIWYG HTML editor. In affected version a vulnerability has been discovered in the core HTML processing module and may affect all plugins used by CKEditor 4. 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 version < 4.17.0. The problem has been recognized and patched. The fix will be available in version 4.17.0. (2021-11-17, CVE-2021-41165)

CKEditor4 is an open source WYSIWYG HTML editor. In affected versions a vulnerability has been discovered in the Advanced Content Filter (ACF) module and may affect all plugins used by CKEditor 4. 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. The problem has been recognized and patched. The fix will be available in version 4.17.0. (2021-11-17, CVE-2021-41164)

ckeditor is an open source WYSIWYG HTML editor with rich content support. A potential vulnerability has been discovered in CKEditor 4 [Fake Objects](https://ckeditor.com/cke4/addon/fakeobjects) package. The vulnerability allowed to inject malformed Fake Objects HTML, which could result in executing JavaScript code. It affects all users using the CKEditor 4 plugins listed above at version < 4.16.2. The problem has been recognized and patched. The fix will be available in version 4.16.2. (2021-08-13, CVE-2021-37695)

ckeditor is an open source WYSIWYG HTML editor with rich content support. A potential vulnerability has been discovered in CKEditor 4 [Clipboard](https://ckeditor.com/cke4/addon/clipboard) package. The vulnerability allowed to abuse paste functionality using malformed HTML, which could result in injecting arbitrary HTML into the editor. It affects all users using the CKEditor 4 plugins listed above at version >= 4.5.2. The problem has been recognized and patched. The fix will be available in version 4.16.2. (2021-08-12, CVE-2021-32809)

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 version >= 4.13.0. The problem has been recognized and patched. The fix will be available in version 4.16.2. (2021-08-12, CVE-2021-32808)

A cross-site scripting (XSS) vulnerability in the HTML Data Processor in CKEditor 4 4.14.0 through 4.16.x before 4.16.1 allows remote attackers to inject executable JavaScript code through a crafted comment because --!> is mishandled. (2021-06-09, CVE-2021-33829)

A cross-site scripting (XSS) vulnerability in the Color Dialog plugin for CKEditor 4.15.0 allows remote attackers to run arbitrary web script after persuading a user to copy and paste crafted HTML code into one of editor inputs. (2020-11-12, CVE-2020-27193)

A cross-site scripting (XSS) vulnerability in the WSC plugin through 5.5.7.5 for CKEditor 4 allows remote attackers to run arbitrary web script inside an IFRAME element by injecting a crafted HTML element into the editor. (2020-03-10, CVE-2020-9440)

A cross-site scripting (XSS) vulnerability in the HTML Data Processor for CKEditor 4.0 before 4.14 allows remote attackers to inject arbitrary web script through a crafted "protected" comment (with the cke_protected syntax). (2020-03-07, CVE-2020-9281)

CKEditor 4.x before 4.11.0 allows user-assisted XSS involving a source-mode paste. (2018-11-14, CVE-2018-17960)

Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.

The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:

https://server.com/confirmation?message=Transaction+Complete

what results in:

<span>Confirmation: Transaction Complete</span>

In that case the message can be modified to become a valid Javascript code, e.g.:

https://server.com/confirmation?message=<script>dangerous javascript code here</script>

and it will be executed locally by the user's browser with full access to the user's personal application/browser data:

<span>Confirmation: <script>dangerous javascript code here</script></span>