Package Instance

Trix has a cross-site Scripting vulnerability on copy & paste
The Trix editor, versions prior to 2.1.4, is vulnerable to XSS when pasting malicious code. This vulnerability is a bypass of the fix put in place for https://github.com/basecamp/trix/security/advisories/GHSA-qjqp-xr96-cj99. In https://github.com/basecamp/trix/pull/1149, we added sanitation for Trix attachments with a `text/html` content type. However, Trix only checks the content type on the paste event's `dataTransfer` object. As long as the `dataTransfer` has a content type of `text/html`, Trix parses its contents and creates an `Attachment` with them, even if the attachment itself doesn't have a `text/html` content type. Trix then uses the attachment content to set the attachment element's `innerHTML`.

Trix vulnerable to Cross-site Scripting on copy & paste
The Trix editor, in versions prior to 2.1.15, is vulnerable to XSS attacks when pasting malicious code.

An attacker could trick a user to copy and paste malicious code that would execute arbitrary JavaScript code within the context of the user's session, potentially leading to unauthorized actions being performed or sensitive information being disclosed.

Trix has a Stored XSS vulnerability through serialized attributes
The Trix editor, in versions prior to 2.1.17, is vulnerable to XSS attacks when a `data-trix-serialized-attributes` attribute bypasses the DOMPurify sanitizer.

An attacker could craft HTML containing a `data-trix-serialized-attributes` attribute with a malicious payload that, when the content is rendered, could execute arbitrary JavaScript code within the context of the user's session, potentially leading to unauthorized actions being performed or sensitive information being disclosed.

Trix allows Cross-site Scripting via `javascript:` url in a link
The Trix editor, versions prior to 2.1.11, is vulnerable to XSS when pasting malicious code in the link field.

Trix is vulnerable to XSS through JSON deserialization bypass in drag-and-drop (Level0InputController)
### Impact

The Trix editor, in versions prior to 2.1.18, is vulnerable to XSS
when a crafted `application/x-trix-document` JSON payload is dropped
into the editor in environments using the fallback Level0InputController
(e.g., embedded WebViews lacking Input Events Level 2 support).

The `StringPiece.fromJSON` method trusted `href` attributes from the
JSON payload without sanitization. An attacker could craft a draggable
element containing a `javascript:` URI in the href attribute that,
when dropped into a vulnerable editor, would bypass DOMPurify
sanitization and inject executable JavaScript into the DOM.

Exploitation requires a specific environment (Level0InputController
fallback) and social engineering (victim must drag and drop
attacker-controlled content into the editor). Applications using
server-side HTML sanitization (such as Rails' built-in sanitizer)
are additionally protected, as the payload is neutralized on save.

### Patches

Update Recommendation: Users should upgrade to Trix editor
version 2.1.18 or later.

### References

The XSS vulnerability was responsibly reported by Hackerone
researcher [newbiefromcoma](https://hackerone.com/newbiefromcoma).

Trix has a stored XSS vulnerability through its attachment attribute
The Trix editor, in versions prior to 2.1.16, is vulnerable to XSS attacks through attachment payloads.

An attacker could inject malicious code into a data-trix-attachment attribute that, when rendered as HTML and clicked on, could execute arbitrary JavaScript code within the context of the user's session, potentially leading to unauthorized actions being performed or sensitive information being disclosed.

Trix editor subject to XSS vulnerabilities on copy & paste
The Trix editor, in versions prior to 2.1.9 and 1.3.3, is vulnerable to XSS + mutation XSS attacks when pasting malicious code.

Arbitrary Code Execution Vulnerability in Trix Editor included in ActionText
From version 7.0 onwards the ActionText gem includes a copy of the Trix rich text editor.
Prior to versions 7.0.8.3 and 7.1.3.3, ActionText included a version of Trix that
is vulnerable to arbitrary code execution when
copying and pasting content from the web or other documents with markup into the editor.
The vulnerability stems from improper sanitization of pasted content, allowing an attacker
to embed malicious scripts which are executed within the context of the application.

# Vulnerable Versions:
  * 7.1 series older than 7.1.3.3
  * 7.0 series older than 7.0.8.3

# Fixed Versions:
  * 7.1.3.3
  * 7.0.8.3

# Vector:

Bug 1: When copying content manipulated by a script, such as:
```javascript
document.addEventListener('copy', function(e){
  e.clipboardData.setData('text/html', '<div><noscript><div class="123</noscript>456<img src=1 onerror=alert(1)//"></div></noscript></div>');
  e.preventDefault();
});
```
and pasting into the Trix editor, the script within the content is executed.

Bug 2: Similar execution occurs with content structured as:

```javascript
document.write(`copy<div data-trix-attachment="{&quot;contentType&quot;:&quot;text/html&quot;,&quot;content&quot;:&quot;&lt;img src=1 onerror=alert(101)&gt;HELLO123&quot;}"></div>me`);
```

# Impact:

An attacker could exploit these vulnerabilities to execute arbitrary JavaScript code
within the context of the user's session, potentially leading to unauthorized actions
being performed or sensitive information being disclosed.

# Remediation:

Update Recommendation: Users of ActionText 7.0 should upgrade to ActionText version 7.0.8.3 or later.
Users of ActionText 7.1 should upgrade to version 7.1.3.3 or later.
These updated versions incorporate proper sanitization of input from copied content.

CSP Enhancement: Additionally, enhancing the Content Security Policy (CSP) to disallow inline scripts
can significantly mitigate the risk of such vulnerabilities.
Set CSP policies such as script-src 'self' to ensure that only scripts hosted on the same origin
are executed, and explicitly prohibit inline scripts using script-src-elem.