CVE-2017-16017 in Sanitize-html
Summary
by MITRE
sanitize-html is a library for scrubbing html input for malicious values Versions 1.2.2 and below have a cross site scripting vulnerability.
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Analysis
by VulDB Data Team • 03/21/2023
The sanitize-html library vulnerability CVE-2017-16017 represents a critical cross site scripting flaw that affects versions 1.2.2 and earlier. This vulnerability stems from inadequate input validation and sanitization mechanisms within the library's processing logic, allowing malicious actors to inject harmful script code into HTML content. The issue specifically manifests when the library fails to properly escape or remove potentially dangerous HTML elements and attributes that could execute malicious JavaScript when rendered in web browsers.
The technical flaw resides in the library's insufficient handling of HTML entities and script tags during the sanitization process. When developers integrate this library into their applications to filter user input, the vulnerability creates a pathway for attackers to bypass security measures by exploiting the library's incomplete sanitization routines. The flaw particularly affects scenarios where user-generated content is processed through the library before being stored or displayed, making it a significant concern for web applications that rely on HTML input filtering.
From an operational impact perspective, this vulnerability exposes applications to persistent cross site scripting attacks where attackers can inject malicious scripts that execute in users' browsers. The consequences extend beyond simple data theft to include session hijacking, credential theft, and potential full system compromise through advanced attack vectors. The vulnerability affects any application using sanitize-html version 1.2.2 or earlier, creating widespread exposure across numerous web applications and services that depend on this popular library for HTML sanitization.
Organizations should immediately upgrade to sanitize-html version 1.2.3 or later, which contains the necessary patches to address the XSS vulnerability. Security teams should conduct comprehensive vulnerability assessments to identify all instances of the affected library within their application ecosystem. Additionally, implementing proper input validation at multiple layers, including server-side and client-side controls, provides defense-in-depth protection. The vulnerability aligns with CWE-79 which specifically addresses cross site scripting flaws, and maps to ATT&CK technique T1211 for external remote code execution through web application vulnerabilities. Organizations should also consider implementing web application firewalls and content security policies as additional protective measures to mitigate potential exploitation attempts.