Ruby/actionview/6.0.0.beta3

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)

Potential XSS vulnerability 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, the default string is incorrectly marked as HTML-safe and not escaped. Vulnerable code may look like the following examples:

<%# 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]) %>

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):

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

Possible XSS vulnerability in ActionView

There is a possible XSS vulnerability in ActionView's JavaScript literal escape helpers. Views that use the j or escape_javascript methods may be susceptible to XSS attacks.

Versions Affected: All. Not affected: None. Fixed Versions: 6.0.2.2, 5.2.4.2

Impact

There is a possible XSS vulnerability in the j and escape_javascript methods in ActionView. These methods are used for escaping JavaScript string literals. Impacted code will look something like this:

<script>let a = `<%= j unknown_input %>`</script>

or

<script>let a = `<%= escape_javascript unknown_input %>`</script>

Releases

The 6.0.2.2 and 5.2.4.2 releases are available at the normal locations.

Workarounds

For those that can't upgrade, the following monkey patch may be used:

ActionView::Helpers::JavaScriptHelper::JS_ESCAPE_MAP.merge!(
  {
    "`" => "\\`",
    "$" => "\\$"
  }
)

module ActionView::Helpers::JavaScriptHelper
  alias :old_ej :escape_javascript
  alias :old_j :j

  def escape_javascript(javascript)
    javascript = javascript.to_s
    if javascript.empty?
      result = ""
    else
      result = javascript.gsub(/(\\|<\/|\r\n|\342\200\250|\342\200\251|[\n\r"']|[`]|[$])/u, JS_ESCAPE_MAP)
    end
    javascript.html_safe? ? result.html_safe : result
  end

  alias :j :escape_javascript
end

CSRF Vulnerability in rails-ujs

There is an 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

Possible XSS Vulnerability in Action View tag helpers

There is a possible XSS vulnerability in Action View tag helpers. Passing untrusted input as hash keys can lead to a possible XSS vulnerability. This vulnerability has been assigned the CVE identifier CVE-2022-27777.

Versions Affected: ALL Not affected: NONE Fixed Versions: 7.0.2.4, 6.1.5.1, 6.0.4.8, 5.2.7.1

Impact

If untrusted data is passed as the hash key for tag attributes, there is a possibility that the untrusted data may not be properly escaped which can lead to an XSS vulnerability.

Impacted code will look something like this:

check_box_tag('thename', 'thevalue', false, aria: { malicious_input => 'thevalueofaria' })

Where the malicious_input variable contains untrusted data.

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

Escape the untrusted data before using it as a key for tag helper methods.

DOM Based Cross-site Scripting in rails-ujs for 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)