Possible XSS Vulnerability in Action Controller

There is a possible XSS vulnerability when using the translation helpers
(translate, t, etc) in Action Controller. This vulnerability has been
assigned the CVE identifier CVE-2024-26143.

Versions Affected: >= 7.0.0.
Not affected: < 7.0.0
Fixed Versions: 7.1.3.1, 7.0.8.1

Impact

Applications using translation methods like translate, or t on a
controller, with a key ending in "_html", a :default key which contains
untrusted user input, and the resulting string is used in a view, may be
susceptible to an XSS vulnerability.

For example, impacted code will look something like this:

class ArticlesController < ApplicationController
  def show  
    @message = t("message_html", default: untrusted_input)
    # The `show` template displays the contents of `@message`
  end
end

To reiterate the pre-conditions, applications must:

• Use a translation function from a controller (i.e. not I18n.t, or t from
  a view)
• Use a key that ends in _html
• Use a default value where the default value is untrusted and unescaped input
• Send the text to the victim (whether that's part of a template, or a
  render call)

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

Releases

The fixed releases are available at the normal locations.

Workarounds

There are no feasible workarounds for this issue.

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.

• 7-0-VULN.patch - Patch for 7.0 series
• 7-1-VULN.patch - Patch for 7.1 series

Credits

Thanks to ooooooo_q for the patch and fix!