VYPR
High severity7.1NVD Advisory· Published Apr 17, 2024· Updated Apr 15, 2026

CVE-2024-32463

CVE-2024-32463

Description

phlex is an open source framework for building object-oriented views in Ruby. There is a potential cross-site scripting (XSS) vulnerability that can be exploited via maliciously crafted user data. The filter to detect and prevent the use of the javascript: URL scheme in the href attribute of an <a> tag could be bypassed with tab \t or newline \n characters between the characters of the protocol, e.g. java\tscript:. This vulnerability is fixed in 1.10.1, 1.9.2, 1.8.3, 1.7.2, 1.6.3, 1.5.3, and 1.4.2. Configuring a Content Security Policy that does not allow unsafe-inline would effectively prevent this vulnerability from being exploited.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
phlexRubyGems
>= 1.10.0, < 1.10.11.10.1
phlexRubyGems
>= 1.9.0, < 1.9.21.9.2
phlexRubyGems
>= 1.8.0, < 1.8.31.8.3
phlexRubyGems
>= 1.7.0, < 1.7.21.7.2
phlexRubyGems
>= 1.6.0, < 1.6.31.6.3
phlexRubyGems
>= 1.5.0, < 1.5.31.5.3
phlexRubyGems
< 1.4.21.4.2

Patches

9
9e3f5b980655

Fix XSS

https://github.com/phlex-ruby/phlexJoel DrapperApr 16, 2024via ghsa
2 files changed · +73 1
  • lib/phlex/sgml.rb+1 1 modified
    @@ -382,7 +382,7 @@ def __attributes__(attributes, buffer = +"")
     				end
     
     				lower_name = name.downcase
    -				next if lower_name == "href" && v.start_with?(/\s*javascript:/i)
    +				next if lower_name == "href" && v.to_s.downcase.tr("\t \n", "").start_with?("javascript:")
     
     				# Detect unsafe attribute names. Attribute names are considered unsafe if they match an event attribute or include unsafe characters.
     				if HTML::EVENT_ATTRIBUTES.include?(lower_name) || name.match?(/[<>&"']/)
    
  • test/phlex/view/naughty_business.rb+72 0 modified
    @@ -85,6 +85,78 @@ def view_template
     		end
     	end
     
    +	with "naughty javascript link protocol with a hidden tab character" do
    +		view do
    +			def view_template
    +				a(href: "\tjavascript:alert(1)") { "XSS" }
    +				a(href: "j\tavascript:alert(1)") { "XSS" }
    +				a(href: "ja\tvascript:alert(1)") { "XSS" }
    +				a(href: "jav\tascript:alert(1)") { "XSS" }
    +				a(href: "java\tscript:alert(1)") { "XSS" }
    +				a(href: "javas\tcript:alert(1)") { "XSS" }
    +				a(href: "javasc\tript:alert(1)") { "XSS" }
    +				a(href: "javascr\tipt:alert(1)") { "XSS" }
    +				a(href: "javascri\tpt:alert(1)") { "XSS" }
    +				a(href: "javascrip\tt:alert(1)") { "XSS" }
    +				a(href: "javascript\t:alert(1)") { "XSS" }
    +				a(href: "javascript:\talert(1)") { "XSS" }
    +			end
    +		end
    +
    +		it "strips the javascript protocol" do
    +			expect(output.scan("<a>").size).to be == 12
    +			expect(output.scan("href").size).to be == 0
    +		end
    +	end
    +
    +	with "naughty javascript link protocol with a hidden newline character" do
    +		view do
    +			def view_template
    +				a(href: "\njavascript:alert(1)") { "XSS" }
    +				a(href: "j\navascript:alert(1)") { "XSS" }
    +				a(href: "ja\nvascript:alert(1)") { "XSS" }
    +				a(href: "jav\nascript:alert(1)") { "XSS" }
    +				a(href: "java\nscript:alert(1)") { "XSS" }
    +				a(href: "javas\ncript:alert(1)") { "XSS" }
    +				a(href: "javasc\nript:alert(1)") { "XSS" }
    +				a(href: "javascr\nipt:alert(1)") { "XSS" }
    +				a(href: "javascri\npt:alert(1)") { "XSS" }
    +				a(href: "javascrip\nt:alert(1)") { "XSS" }
    +				a(href: "javascript\n:alert(1)") { "XSS" }
    +				a(href: "javascript:\nalert(1)") { "XSS" }
    +			end
    +		end
    +
    +		it "strips the javascript protocol" do
    +			expect(output.scan("<a>").size).to be == 12
    +			expect(output.scan("href").size).to be == 0
    +		end
    +	end
    +
    +	with "naughty javascript link protocol with a hidden whitespace character" do
    +		view do
    +			def view_template
    +				a(href: " javascript:alert(1)") { "XSS" }
    +				a(href: "j avascript:alert(1)") { "XSS" }
    +				a(href: "ja vascript:alert(1)") { "XSS" }
    +				a(href: "jav ascript:alert(1)") { "XSS" }
    +				a(href: "java script:alert(1)") { "XSS" }
    +				a(href: "javas cript:alert(1)") { "XSS" }
    +				a(href: "javasc ript:alert(1)") { "XSS" }
    +				a(href: "javascr ipt:alert(1)") { "XSS" }
    +				a(href: "javascri pt:alert(1)") { "XSS" }
    +				a(href: "javascrip t:alert(1)") { "XSS" }
    +				a(href: "javascript :alert(1)") { "XSS" }
    +				a(href: "javascript: alert(1)") { "XSS" }
    +			end
    +		end
    +
    +		it "strips the javascript protocol" do
    +			expect(output.scan("<a>").size).to be == 12
    +			expect(output.scan("href").size).to be == 0
    +		end
    +	end
    +
     	Phlex::HTML::EVENT_ATTRIBUTES.each do |event_attribute|
     		with "with naughty #{event_attribute} attribute" do
     			naughty_attributes = { event_attribute => "alert(1);" }
    

Vulnerability mechanics

Generated by null/stub on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

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