CyberRota Analysis
AI-GeneratedThe vulnerability exists in the CSS scrubber of the html_sanitize_ex library, allowing unauthenticated remote attackers to inject CSS at-rules, including remote stylesheet imports, into web pages served to other users. Although the injected content is contained within the <style> element and does not execute scripts, it can lead to unauthorized styling changes and potential phishing attacks. Organizations using affected versions of html_sanitize_ex (from 0.3.1 to before 1.5.4) should prioritize patching to mitigate this risk.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to inject CSS at-rules, including an import of a remote stylesheet, into a page served to other users. HtmlSanitizeEx.Scrubber.CSS.scrub/1 applies its property and value allowlist through a Regex.replace over substrings matching a property: value declaration pattern, so input that does not match that pattern is never inspected and is copied to the output unchanged. @import url(//attacker.example/style.css); survives, while the same URL inside a background: url(...) declaration is removed. Element boundaries are resolved before the scrubber runs, so injected content does not escape the <style> element and no script executes. This issue affects html_sanitize_ex: from 0.3.1 before 1.5.4.
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