CVE-2010-3770 in Firefox
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in the rendering engine in Mozilla Firefox before 3.5.16 and 3.6.x before 3.6.13, and SeaMonkey before 2.0.11, allow remote attackers to inject arbitrary web script or HTML via (1) x-mac-arabic, (2) x-mac-farsi, or (3) x-mac-hebrew characters that may be converted to angle brackets during rendering.
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Analysis
by VulDB Data Team • 12/08/2024
This vulnerability represents a critical cross-site scripting flaw affecting major web browsers including firefox and seamonkey. The issue stems from how these browsers handle specific character encodings during rendering processes, particularly when processing macintosh character sets such as x-mac-arabic, x-mac-farsi, and x-mac-hebrew. These character encodings contain specific byte sequences that during the rendering process are converted into angle brackets which are then interpreted as HTML tags by the browser's rendering engine. The vulnerability exists because the browsers fail to properly sanitize or escape these converted characters before displaying them to users, creating an avenue for attackers to inject malicious javascript code or html content directly into web pages.
The technical exploitation of this vulnerability occurs when a malicious actor crafts content using these specific character encodings in web forms, email messages, or web content that gets rendered by affected browsers. When the browser encounters these encoded characters during the rendering phase, the conversion process transforms specific byte sequences into angle brackets which are then interpreted by the browser as HTML markup. This conversion process bypasses normal input sanitization mechanisms because the malicious content appears legitimate during the initial processing stages but becomes dangerous only during the final rendering phase. The vulnerability affects multiple browser versions simultaneously, indicating a fundamental flaw in how these browsers handle character encoding conversions rather than isolated implementation issues.
The operational impact of this vulnerability is significant as it allows remote attackers to execute arbitrary javascript code in the context of the victim's browser session. This creates numerous attack vectors including session hijacking, credential theft, data exfiltration, and redirection to malicious websites. Attackers can leverage this vulnerability to perform phishing attacks, inject malicious advertisements, or deliver malware through browser-based exploits. The vulnerability is particularly dangerous because it can be exploited through various means including web forms, email attachments, or content management systems that process user input. The attack requires no special privileges or complex exploitation techniques, making it a high-risk vulnerability that affects a broad user base.
Mitigation strategies for this vulnerability include immediate patching of affected browser versions to the latest secure releases. Users should ensure their firefox and seamonkey installations are updated to versions 3.5.16, 3.6.13, or 2.0.11 respectively, which contain the necessary fixes for this character encoding conversion issue. Organizations should implement comprehensive input validation and sanitization measures at application level, particularly when processing user-generated content that may contain international character sets. Network administrators should consider implementing web application firewalls and content filtering solutions to detect and block suspicious character encoding patterns. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and maps to ATT&CK technique T1566 which covers social engineering through spearphishing with malicious attachments or links. Regular security updates and browser hardening practices remain essential for protecting against similar encoding-based vulnerabilities that may arise in the future.