CVE-2024-29203
TinyMCE Cross-Site Scripting (XSS) vulnerability in handling iframes
Impact
### Impact A [cross-site scripting (XSS)](https://owasp.org/www-community/attacks/xss/) vulnerability was discovered in TinyMCE’s content insertion code. This allowed `iframe` elements containing malicious code to execute when inserted into the editor. These `iframe` elements are restricted in their permissions by same-origin browser protections, but could still trigger operations such as downloading of malicious assets. ### Fix TinyMCE 6.8.1 introduced a new `sandbox_iframes` boolean option which adds the `sandbox=""` attribute to every `iframe` element by default when enabled. This will prevent cross-origin, and in special cases same-origin, XSS by embedded resources in `iframe` elements. From TinyMCE 7.0.0 onwards the default value of this option is `true`. In TinyMCE 7.0.0 a new `sandbox_iframes_exclusions` option was also added, allowing a list of domains to be specified that should be excluded from having the `sandbox=""` attribute applied when the `sandbox_iframes` option is enabled. By default, this option is set to an array of domains that are provided in embed code by popular websites. To sandbox `iframe` elements from every domain, set this option to `[]`. ### Workarounds The HTTP Content-Security-Policy (CSP) `frame-src` or `object-src` can be configured to restrict or block the loading of unauthorized URLS. Refer to the [TinyMCE Content Security Policy Guide](https://www.tiny.cloud/docs/tinymce/latest/tinymce-and-csp/). ### References - [TinyMCE 6.8.1](https://www.tiny.cloud/docs/tinymce/6/6.8.1-release-notes/#new-convert_unsafe_embeds-option-that-controls-whether-object-and-embed-elements-will-be-converted-to-more-restrictive-alternatives-namely-img-for-image-mime-types-video-for-video-mime-types-audio-audio-mime-types-or-iframe-for-other-or-unspecified-mime-types) - [TinyMCE 7.0.0](https://www.tiny.cloud/docs/tinymce/7/7.0-release-notes/#sandbox_iframes-editor-option-is-now-defaulted-to-true)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | tinymce | < 6.8.1 | 6.8.1 |
| nuget | TinyMCE | < 6.8.1 | 6.8.1 |
| composer | tinymce/tinymce | < 6.8.1 | 6.8.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Tiny | Tinymce | before 6.8.1 from 6.8.2 before 7.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/tinymce/tinymce/commit/bcdea2ad14e3c2cea40743fb48c63bba067ae6d1
- https://github.com/tinymce/tinymce/security/advisories/GHSA-438c-3975-5x3f
- https://www.tiny.cloud/docs/tinymce/6/6.8.1-release-notes/#new-convert_unsafe_embeds-option-that-controls-whether-object-and-embed-elements-will-be-converted-to-more-restrictive-alternatives-namely-img-for-image-mime-types-video-for-video-mime-types-audio-audio-mime-types-or-iframe-for-other-or-unspecified-mime-types
- https://www.tiny.cloud/docs/tinymce/7/7.0-release-notes/#sandbox_iframes-editor-option-is-now-defaulted-to-true
- https://github.com/advisories/GHSA-438c-3975-5x3f
- https://nvd.nist.gov/vuln/detail/CVE-2024-29203