CVE-2022-23519: Possible XSS vulnerability with certain configurations of rails-html-sanitizer

First published: Tue Dec 13 2022(Updated: )

## 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.action_view.sanitized_allowed_tags = ["math", "style"] # or config.action_view.sanitized_allowed_tags = ["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 `allowed_tags=`: ```ruby # class-level option Rails::Html::SafeListSanitizer.allowed_tags = ["math", "style"] # or Rails::Html::SafeListSanitizer.allowed_tags = ["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://cwe.mitre.org/data/definitions/79.html) - https://hackerone.com/reports/1656627 ## Credit This vulnerability was responsibly reported by Dominic Breuker.

Credit: security-advisories@github.com security-advisories@github.com security-advisories@github.com

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

• collector/github-advisory-latest
• alias/GHSA-9h9g-93gc-623h
• alias/CVE-2022-23519
• collector/github-advisory
• collector/redhat-cve
• collector/nvd-index
• collector/nvd-cve
• agent/type
• agent/first-publish-date
• agent/references
• agent/weakness
• agent/author
• agent/severity
• collector/redhat-bugzilla
• source/Red Hat
• agent/software-canonical-lookup
• collector/nvd-api
• source/NVD
• agent/softwarecombine
• agent/description
• collector/mitre-cve
• source/MITRE
• agent/title
• agent/last-modified-date
• agent/event
• agent/tags
• package-manager/rubygems
• package-manager/redhat
• vendor/rails html sanitizer project
• canonical/rails html sanitizer project rails html sanitizer
• vendor/rubyonrails
• canonical/rubyonrails rails html sanitizers
• vendor/debian
• canonical/debian debian linux
• version/debian debian linux/10.0