GHSA-242p-4v39-2v8g Cross-site Scripting (XSS) possible with maliciously formed HTML attribute names and values in Phlex

• RubyGems phlex: >= 1.9.0, < 1.9.1 → fixed in 1.9.1 • RubyGems phlex: >= 1.8.0, < 1.8.2 → fixed in 1.8.2 • RubyGems phlex: >= 1.7.0, < 1.7.1 → fixed in 1.7.1 • RubyGems phlex: >= 1.6.0, < 1.6.2 → fixed in 1.6.2 • RubyGems phlex: >= 1.5.0, < 1.5.2 → fixed in 1.5.2 • RubyGems phlex: >= 1.4.0, < 1.4.1 → fixed in 1.4.1 • RubyGems phlex: >= 1.3.0, < 1.3.3 → fixed in 1.3.3 • RubyGems phlex: >= 1.2.0, < 1.2.2 → fixed in 1.2.2 • RubyGems phlex: >= 1.1.0, < 1.1.1 → fixed in 1.1.1 • RubyGems phlex: < 1.0.1 → fixed in 1.0.1

There is a potential cross-site scripting (XSS) vulnerability that can be exploited via maliciously crafted user data. This was due to improper case-sensitivity in the code that was meant to prevent these attacks. Impact If you render an `` tag with an `href` attribute set to a user-provided link, that link could potentially execute JavaScript when clicked by another user. ```ruby a(href: user_profile) { "Profile" } ``` If you splat user-provided attributes when rendering any HTML or SVG tag, malicious event attributes could be included in the output, executing JavaScript when the events are triggered by another user. ```ruby h1(**JSON.parse(user_attributes)) ``` Patches Patches are available on RubyGems for all `1.x` minor versions. The patched versions are: • 1.9.1 • 1.8.2 • 1.7.1 • 1.6.2 • 1.5.2 • 1.4.1 • 1.3.3 • 1.2.2 • 1.1.1 • 1.0.1 If you are on `main`, it has been patched since `aa50c60` Workarounds Configuring a Content Security Policy that does not allow `unsafe-inline` would effectively prevent this vulnerability from being exploited. References In addition to upgrading to a patched version of Phlex, we strongly recommend configuring a Content Security Policy header that does not allow `unsafe-inline`. Here’s how you can configure a Content Security Policy header in Rails. https://guides.rubyonrails.org/security.html#content-security-policy-header