rails-html-sanitizer contains an incomplete fix for an XSS vulnerability
rails-html-sanitizer is responsible for sanitizing HTML fragments in Rails applications. Prior to version 1.4.4, there is a possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer due to an incomplete fix of CVE-2022-32209. 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. This issue is patched in version 1.4.4. All users overriding the allowed tags to include both "select" and "style" should either upgrade or use this workaround: Remove either "select" or "style" from the overridden allowed tags. NOTE: Code is _not_ impacted if allowed tags are overridden using either the :tags option to the Action View helper method sanitize or the :tags option to the instance method SafeListSanitizer#sanitize.
02 / AFFECTED SOFTWARE
Affected packages
12 explicit affected versions
12 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
## 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.action_view.sanitized_allow_tags=`: ```ruby # In config/application.rb config.action_view.sanitized_allowed_tags = ["select", "style"] ``` (see https://guides.rubyonrails.org/configuring.html#configuring-action-view) 2. Using the class method `Rails::Html::SafeListSanitizer.allowed_tags=`: ```ruby # class-level option Rails::Html::SafeListSanitizer.allowed_tags = ["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://cwe.mitre.org/data/definitions/79.html) - 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.
rails-html-sanitizer is responsible for sanitizing HTML fragments in Rails applications. Prior to version 1.4.4, there is a possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer due to an incomplete fix of CVE-2022-32209. 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. This issue is patched in version 1.4.4. All users overriding the allowed tags to include both "select" and "style" should either upgrade or use this workaround: Remove either "select" or "style" from the overridden allowed tags. NOTE: Code is _not_ impacted if allowed tags are overridden using either the :tags option to the Action View helper method sanitize or the :tags option to the instance method SafeListSanitizer#sanitize.
05 / REFERENCES
Further evidence
- https://github.com/rails/rails-html-sanitizer
- https://github.com/rails/rails-html-sanitizer/security/advisories/GHSA-rrfc-7g8p-99q8
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rails-html-sanitizer/CVE-2022-23520.yml
- https://hackerone.com/reports/1654310
- https://lists.debian.org/debian-lts-announce/2023/09/msg00012.html
- https://lists.debian.org/debian-lts-announce/2024/09/msg00045.html
- https://nvd.nist.gov/vuln/detail/CVE-2022-23520
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/23xxx/CVE-2022-23520.json