{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rails-html-sanitizer"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.6.0"
            },
            {
              "fixed": "1.6.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.6.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2024-53987"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-12-02T21:48:56Z",
    "nvd_published_at": "2024-12-02T22:15:11Z",
    "severity": "LOW"
  },
  "details": "## Summary\n\nThere is a possible XSS vulnerability with certain configurations of Rails::HTML::Sanitizer 1.6.0 when used with Rails \u003e= 7.1.0.\n\n* Versions affected: 1.6.0\n* Not affected: \u003c 1.6.0\n* Fixed versions: 1.6.1\n\n## Impact\n\nA possible XSS vulnerability with certain configurations of Rails::HTML::Sanitizer may allow an attacker to inject content if HTML5 sanitization is enabled and the application developer has overridden the sanitizer\u0027s allowed tags in the following way:\n\n- the \"style\" element is explicitly allowed\n- the \"svg\" or \"math\" element is not allowed\n\nCode is only impacted if Rails is configured to use HTML5 sanitization, please see documentation for [`config.action_view.sanitizer_vendor`](https://guides.rubyonrails.org/configuring.html#config-action-view-sanitizer-vendor) and [`config.action_text.sanitizer_vendor`](https://guides.rubyonrails.org/configuring.html#config-action-text-sanitizer-vendor) for more information on these configuration options.\n\nThe default configuration is to disallow all of these elements. Code is only impacted if allowed tags are being overridden. Applications may be doing this in a few different ways:\n\n1. using application configuration to configure Action View sanitizers\u0027 allowed tags:\n\n  ```ruby\n  # In config/application.rb\n  config.action_view.sanitized_allowed_tags = [\"style\"]\n  ```\n\n  see https://guides.rubyonrails.org/configuring.html#configuring-action-view\n\n2. using a `:tags` option to the Action View helper `sanitize`:\n\n  ```\n  \u003c%= sanitize @comment.body, tags: [\"style\"] %\u003e\n  ```\n\n  see https://api.rubyonrails.org/classes/ActionView/Helpers/SanitizeHelper.html#method-i-sanitize\n\n3. setting Rails::HTML5::SafeListSanitizer class attribute `allowed_tags`:\n\n  ```ruby\n  # class-level option\n  Rails::HTML5::SafeListSanitizer.allowed_tags = [\"style\"]\n  ```\n\n  (note that this class may also be referenced as `Rails::Html::SafeListSanitizer`)\n\n4. using a `:tags` options to the Rails::HTML5::SafeListSanitizer instance method `sanitize`:\n\n  ```ruby\n  # instance-level option\n  Rails::HTML5::SafeListSanitizer.new.sanitize(@article.body, tags: [\"style\"])\n  ```\n\n  (note that this class may also be referenced as `Rails::Html::SafeListSanitizer`)\n\n5. setting ActionText::ContentHelper module attribute `allowed_tags`:\n\n  ```ruby\n  ActionText::ContentHelper.allowed_tags = [\"style\"]\n  ```\n\nAll users overriding the allowed tags by any of the above mechanisms to include \"style\" and omit \"svg\" or \"math\" should either upgrade or use one of the workarounds.\n\n\n## Workarounds\n\nAny one of the following actions will work around this issue:\n\n- Remove \"style\" from the overridden allowed tags,\n- Or, downgrade sanitization to HTML4 (see documentation for [`config.action_view.sanitizer_vendor`](https://guides.rubyonrails.org/configuring.html#config-action-view-sanitizer-vendor) and [`config.action_text.sanitizer_vendor`](https://guides.rubyonrails.org/configuring.html#config-action-text-sanitizer-vendor) for more information).\n\n\n## References\n\n- [CWE - CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027) (4.9)](https://cwe.mitre.org/data/definitions/79.html)\n- Original report: https://hackerone.com/reports/2519936\n\n## Credit\n\nThis vulnerability was responsibly reported by So Sakaguchi ([mokusou](https://hackerone.com/mokusou)) and [taise](https://hackerone.com/taise).\n",
  "id": "GHSA-2x5m-9ch4-qgrr",
  "modified": "2024-12-03T18:50:32Z",
  "published": "2024-12-02T21:48:56Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rails/rails-html-sanitizer/security/advisories/GHSA-2x5m-9ch4-qgrr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-53987"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rails/rails-html-sanitizer/commit/f02ffbb8465e73920b6de0da940f5530f855965e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rails/rails-html-sanitizer"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rails-html-sanitizer/CVE-2024-53987.yml"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "rails-html-sanitizer has XSS vulnerability with certain configurations"
}