CVE-2024-21910

Impact

A cross-site scripting (XSS) vulnerability was discovered in the URL processing logic of the image and link plugins. The vulnerability allowed arbitrary JavaScript execution when updating an image or link using a specially crafted URL. This issue only impacted users while editing and the dangerous URLs were stripped in any content extracted from the editor. This impacts all users who are using TinyMCE 5.9.2 or lower.

Patches

This vulnerability has been patched in TinyMCE 5.10.0 by improved sanitization logic when updating URLs in the relevant plugins.

Workarounds

To work around this vulnerability, either:

• Upgrade to TinyMCE 5.10.0 or higher
• Disable the image and link plugins

Acknowledgements

Tiny Technologies would like to thank Yakir6 for discovering this vulnerability.

References

https://www.tiny.cloud/docs/release-notes/release-notes510/#securityfixes

For more information

If you have any questions or comments about this advisory:

• Email us at [email protected]
• Open an issue in the TinyMCE repo

Impact

A cross-site scripting (XSS) vulnerability was discovered in the URL processing logic of the image and link plugins. The vulnerability allowed arbitrary JavaScript execution when updating an image or link using a specially crafted URL. This issue only impacted users while editing and the dangerous URLs were stripped in any content extracted from the editor. This impacts all users who are using TinyMCE 5.9.2 or lower.

Patches

This vulnerability has been patched in TinyMCE 5.10.0 by improved sanitization logic when updating URLs in the relevant plugins.

Workarounds

To work around this vulnerability, either:

• Upgrade to TinyMCE 5.10.0 or higher
• Disable the image and link plugins

Acknowledgements

Tiny Technologies would like to thank Yakir6 for discovering this vulnerability.

References

https://www.tiny.cloud/docs/release-notes/release-notes510/#securityfixes

For more information

If you have any questions or comments about this advisory:

• Email us at [email protected]
• Open an issue in the TinyMCE repo

TinyMCE versions before 5.10.0 are affected by a cross-site scripting vulnerability. A remote and unauthenticated attacker could introduce crafted image or link URLs that would result in the execution of arbitrary JavaScript in an editing user's browser.

TuxCare rebuilt tinymce to address 12 CVEs. Fixed in 4.9.11-tuxcare.1.

Impact

A cross-site scripting (XSS) vulnerability was discovered in the URL sanitization logic of the core parser for form elements. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor using the clipboard or APIs, and then submitting the form. However, as TinyMCE does not allow forms to be submitted while editing, the vulnerability could only be triggered when the content was previewed or rendered outside of the editor. This impacts all users who are using TinyMCE 5.7.0 or lower.

Patches

This vulnerability has been patched in TinyMCE 5.7.1 by improved URL sanitization logic.

Workarounds

To work around this vulnerability, either:

• Upgrade to TinyMCE 5.7.1 or higher
• Manually sanitize form URL attributes using a TinyMCE node filter.
• Disable form elements in your content using the invalid_elements setting.

Example: Sanitizing using a node filter

editor.parser.addNodeFilter('form', function(nodes) {
  nodes.forEach(function(node) {
    if (node.attributes) {
      node.attributes.forEach(function(attr) {
        var name = attr.name;
        var value = attr.value;
        // Sanitize the attribute value here or remove it entirely
        var sanitizedValue = ...;
        node.attr(name, santizedValue);
      });
    }
  });
});

Example: Using invalid_elements

invalid_elements: 'form'

Acknowledgements

Tiny Technologies would like to thank Mikhail Khramenkov at Solar Security Research Team for discovering this vulnerability.

References

https://www.tiny.cloud/docs/release-notes/release-notes571/#securityfixes

For more information

If you have any questions or comments about this advisory:

• Open an issue in the TinyMCE repo
• Email us at [email protected]