Package Instance

rails-ujs vulnerable to DOM Based Cross-site Scripting contenteditable HTML Elements
NOTE: rails-ujs is part of Rails/actionview since 5.1.0.

There is a potential DOM based cross-site scripting issue in rails-ujs
which leverages the Clipboard API to target HTML elements that are
assigned the contenteditable attribute. This has the potential to
occur when pasting malicious HTML content from the clipboard that
includes a data-method, data-remote or data-disable-with attribute.

This vulnerability has been assigned the CVE identifier CVE-2023-23913.

Not affected: < 5.1.0
Versions Affected: >= 5.1.0
Fixed Versions: 6.1.7.3, 7.0.4.3

Impact
If the specified malicious HTML clipboard content is provided to a
contenteditable element, this could result in the arbitrary execution
of javascript on the origin in question.

Releases
The FIXED releases are available at the normal locations.

Workarounds
We recommend that all users upgrade to one of the FIXED versions.
In the meantime, users can attempt to mitigate this vulnerability
by removing the contenteditable attribute from elements in pages
that rails-ujs will interact with.

Patches
To aid users who aren’t able to upgrade immediately we have provided
patches for the two supported release series. They are in git-am
format and consist of a single changeset.

* rails-ujs-data-method-contenteditable-6-1.patch - Patch for 6.1 series
* rails-ujs-data-method-contenteditable-7-0.patch - Patch for 7.0 series

Please note that only the 7.0.Z and 6.1.Z series are
supported at present, and 6.0.Z for severe vulnerabilities.

Users of earlier unsupported releases are advised to upgrade as
soon as possible as we cannot guarantee the continued availability
of security fixes for unsupported releases.

Credits
We would like to thank ryotak 15 for reporting this!

* rails-ujs-data-method-contenteditable-6-1.patch (8.5 KB)
* rails-ujs-data-method-contenteditable-7-0.patch (8.5 KB)
* rails-ujs-data-method-contenteditable-main.patch (8.9 KB)

XSS in Action View
There is a potential Cross-Site Scripting (XSS) vulnerability in Action View's translation helpers. Views that allow the user to control the default (not found) value of the `t` and `translate` helpers could be susceptible to XSS attacks.

### Impact

When an HTML-unsafe string is passed as the default for a missing translation key [named `html` or ending in `_html`](https://guides.rubyonrails.org/i18n.html#using-safe-html-translations), the default string is incorrectly marked as HTML-safe and not escaped. Vulnerable code may look like the following examples:

```erb
<%# The welcome_html translation is not defined for the current locale: %>
<%= t("welcome_html", default: untrusted_user_controlled_string) %>

<%# Neither the title.html translation nor the missing.html translation is defined for the current locale: %>
<%= t("title.html", default: [:"missing.html", untrusted_user_controlled_string]) %>
```

### Patches

Patched Rails versions, 6.0.3.3 and 5.2.4.4, are available from the normal locations.

The patches have also been applied to the `master`, `6-0-stable`, and `5-2-stable` branches on GitHub. If you track any of these branches, you should update to the latest.

To aid users who aren’t able to upgrade immediately, we’ve provided patches for the two supported release series. They are in git-am format and consist of a single changeset.

* [5-2-translate-helper-xss.patch](https://gist.github.com/georgeclaghorn/a466e103922ee81f24c32c9034089442#file-5-2-translate-helper-xss-patch) — patch for the 5.2 release series
* [6-0-translate-helper-xss.patch](https://gist.github.com/georgeclaghorn/a466e103922ee81f24c32c9034089442#file-6-0-translate-helper-xss-patch) — patch for the 6.0 release series

Please note that only the 5.2 and 6.0 release series are currently supported. Users of earlier, unsupported releases are advised to update as soon as possible, as we cannot provide security fixes for unsupported releases.

### Workarounds

Impacted users who can’t upgrade to a patched Rails version can avoid this issue by manually escaping default translations with the `html_escape` helper (aliased as `h`):

```erb
<%= t("welcome_html", default: h(untrusted_user_controlled_string)) %>
```

Path Traversal in Action View
# File Content Disclosure in Action View

Impact 
------ 
There is a possible file content disclosure vulnerability in Action View.  Specially crafted accept headers in combination with calls to `render file:`  can cause arbitrary files on the target server to be rendered, disclosing the  file contents. 

The impact is limited to calls to `render` which render file contents without  a specified accept format.  Impacted code in a controller looks something like this: 

``` ruby
class UserController < ApplicationController 
  def index 
    render file: "#{Rails.root}/some/file" 
  end 
end 
``` 

Rendering templates as opposed to files is not impacted by this vulnerability. 

All users running an affected release should either upgrade or use one of the workarounds immediately. 

Releases 
-------- 
The 6.0.0.beta3, 5.2.2.1, 5.1.6.2, 5.0.7.2, and 4.2.11.1 releases are available at the normal locations. 

Workarounds 
----------- 
This vulnerability can be mitigated by specifying a format for file rendering, like this: 

``` ruby
class UserController < ApplicationController 
  def index 
    render file: "#{Rails.root}/some/file", formats: [:html] 
  end 
end 
``` 

In summary, impacted calls to `render` look like this: 

``` 
render file: "#{Rails.root}/some/file" 
``` 

The vulnerability can be mitigated by changing to this: 

``` 
render file: "#{Rails.root}/some/file", formats: [:html] 
``` 

Other calls to `render` are not impacted. 

Alternatively, the following monkey patch can be applied in an initializer: 

``` ruby
$ cat config/initializers/formats_filter.rb 
# frozen_string_literal: true 

ActionDispatch::Request.prepend(Module.new do 
  def formats 
    super().select do |format| 
      format.symbol || format.ref == "*/*" 
    end 
  end 
end) 
``` 

Credits 
------- 
Thanks to John Hawthorn <john@hawthorn.email> of GitHub

Allocation of Resources Without Limits or Throttling
There is a possible denial of service vulnerability in Action View (Rails)  where specially crafted accept headers can cause action view to consume % cpu and make the server unresponsive.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Multiple cross-site scripting (XSS) vulnerabilities in the mail_to helper in Ruby on Rails before 2.3.11, and 3.x before 3.0.4, when javascript encoding is used, allow remote attackers to inject arbitrary web script or HTML via a crafted (1) name or (2) email value.

CSRF Vulnerability in rails-ujs
There is a vulnerability in rails-ujs that allows attackers to send CSRF tokens to wrong domains.

Versions Affected:  rails <= 6.0.3
Not affected:       Applications which don't use rails-ujs.
Fixed Versions:     rails >= 5.2.4.3, rails >= 6.0.3.1

Impact
------

This is a regression of CVE-2015-1840.

In the scenario where an attacker might be able to control the href attribute of an anchor tag or the action attribute of a form tag that will trigger a POST action, the attacker can set the href or action to a cross-origin URL, and the CSRF token will be sent.

Workarounds
-----------

To work around this problem, change code that allows users to control the href attribute of an anchor tag or the action attribute of a form tag to filter the user parameters.

For example, code like this:

    link_to params

to code like this:

    link_to filtered_params

    def filtered_params
      # Filter just the parameters that you trust
    end