Summary

There is a possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer.

- Versions affected: ALL - Not affected: NONE - Fixed versions: 1.4.4

Impact

A possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer may allow an attacker to inject content if the application developer has overridden the sanitizer's allowed tags in either of the following ways:

- allow both "math" and "style" elements, - or allow both "svg" and "style" elements

Code is only impacted if allowed tags are being overridden. Applications may be doing this in four different ways:

1. using application configuration:

ruby # In config/application.rb config.actionview.sanitizedallowedtags = ["math", "style"] # or config.actionview.sanitizedallowedtags = ["svg", "style"]

see https://guides.rubyonrails.org/configuring.html#configuring-action-view

2. using a :tags option to the Action View helper sanitize:

<%= sanitize @comment.body, tags: ["math", "style"] %> <%# or %> <%= sanitize @comment.body, tags: ["svg", "style"] %>

see https://api.rubyonrails.org/classes/ActionView/Helpers/SanitizeHelper.html#method-i-sanitize

3. using Rails::Html::SafeListSanitizer class method allowedtags=:

ruby # class-level option Rails::Html::SafeListSanitizer.allowedtags = ["math", "style"] # or Rails::Html::SafeListSanitizer.allowedtags = ["svg", "style"]

4. using a :tags options to the Rails::Html::SafeListSanitizer instance method sanitize:

ruby # instance-level option Rails::Html::SafeListSanitizer.new.sanitize(@article.body, tags: ["math", "style"]) # or Rails::Html::SafeListSanitizer.new.sanitize(@article.body, tags: ["svg", "style"])

All users overriding the allowed tags by any of the above mechanisms to include (("math" or "svg") and "style") should either upgrade or use one of the workarounds immediately.

Workarounds

Remove "style" from the overridden allowed tags, or remove "math" and "svg" from the overridden allowed tags.

References

- CWE - CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (4.9) - https://hackerone.com/reports/1656627

Credit

This vulnerability was responsibly reported by Dominic Breuker.

Summary

rails-html-sanitizer >= 1.0.3, < 1.4.4 is vulnerable to cross-site scripting via data URIs when used in combination with Loofah >= 2.1.0.

Mitigation

Upgrade to rails-html-sanitizer >= 1.4.4.

Severity

The maintainers have evaluated this as Medium Severity 6.1.

References

- CWE - CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (4.9) - SVG MIME Type (image/svg+xml) is misleading to developers · Issue #266 · w3c/svgwg - https://github.com/rails/rails-html-sanitizer/issues/135 - https://hackerone.com/reports/1694173

Credit

This vulnerability was independently reported by Maciej Piechota (@haqpl) and Mrinmoy Das (@goromlagche).

Summary

Certain configurations of rails-html-sanitizer < 1.4.4 use an inefficient regular expression that is susceptible to excessive backtracking when attempting to sanitize certain SVG attributes. This may lead to a denial of service through CPU resource consumption.

Mitigation

Upgrade to rails-html-sanitizer >= 1.4.4.

Severity

The maintainers have evaluated this as High Severity 7.5 (CVSS3.1).

References

- CWE - CWE-1333: Inefficient Regular Expression Complexity (4.9) - https://hackerone.com/reports/1684163

Credit

This vulnerability was responsibly reported by @ooooooo-q (https://github.com/ooooooo-q).

Summary

There is a possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer. This is due to an incomplete fix of CVE-2022-32209.

- Versions affected: ALL - Not affected: NONE - Fixed versions: 1.4.4

Impact

A possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer may allow an attacker to inject content if the application developer has overridden the sanitizer's allowed tags to allow both "select" and "style" elements.

Code is only impacted if allowed tags are being overridden using either of the following two mechanisms:

1. Using the Rails configuration config.actionview.sanitizedallowtags=:

ruby # In config/application.rb config.actionview.sanitizedallowedtags = ["select", "style"]

(see https://guides.rubyonrails.org/configuring.html#configuring-action-view)

2. Using the class method Rails::Html::SafeListSanitizer.allowedtags=:

ruby # class-level option Rails::Html::SafeListSanitizer.allowedtags = ["select", "style"]

All users overriding the allowed tags by either of the above mechanisms to include both "select" and "style" should either upgrade or use one of the workarounds immediately.

NOTE: Code is not impacted if allowed tags are overridden using either of the following mechanisms:

- the :tags option to the Action View helper method sanitize. - the :tags option to the instance method SafeListSanitizer#sanitize.

Workarounds

Remove either "select" or "style" from the overridden allowed tags.

References

- CWE - CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (4.9) - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-32209 - https://hackerone.com/reports/1654310

Credit

This vulnerability was responsibly reported by Dominic Breuker.

Cross-site scripting (XSS) vulnerability in the rails-html-sanitizer gem 1.0.2 for Ruby on Rails 4.2.x and 5.x allows remote attackers to inject arbitrary web script or HTML via an HTML entity that is mishandled by the Rails::Html::FullSanitizer class.

Cross-site scripting (XSS) vulnerability in lib/rails/html/scrubbers.rb in the rails-html-sanitizer gem before 1.0.3 for Ruby on Rails 4.2.x and 5.x allows remote attackers to inject arbitrary web script or HTML via a crafted CDATA node.

Cross-site scripting (XSS) vulnerability in the rails-html-sanitizer gem before 1.0.3 for Ruby on Rails 4.2.x and 5.x allows remote attackers to inject arbitrary web script or HTML via crafted tag attributes.

There is a possible XSS vulnerability in all rails-html-sanitizer gem versions below 1.0.4 for Ruby. The gem allows non-whitelisted attributes to be present in sanitized output when input with specially-crafted HTML fragments, and these attributes can lead to an XSS attack on target applications. This issue is similar to CVE-2018-8048 in Loofah. All users running an affected release should either upgrade or use one of the workarounds immediately.