CVE-2008-5504 in Firefox
Summary
by MITRE
Mozilla Firefox 2.x before 2.0.0.19 allows remote attackers to run arbitrary JavaScript with chrome privileges via vectors related to the feed preview, a different vulnerability than CVE-2008-3836.
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Analysis
by VulDB Data Team • 08/03/2021
This vulnerability exists within Mozilla Firefox version 2.x prior to 2.0.0.19 and represents a critical privilege escalation flaw that allows remote attackers to execute arbitrary JavaScript code with chrome privileges. The vulnerability specifically relates to the feed preview functionality within the browser, which creates a pathway for malicious actors to bypass normal security restrictions. Unlike CVE-2008-3836 which addressed a different aspect of feed handling, this flaw focuses on how the browser processes feed preview content, creating an attack surface that can be exploited through crafted feed data. The vulnerability stems from inadequate input validation and privilege separation mechanisms within the browser's feed preview subsystem, allowing attackers to inject malicious JavaScript code that gains elevated privileges typically restricted to browser chrome components. This represents a classic sandbox escape vulnerability where user-supplied content can be manipulated to execute code with the same privileges as the browser's core components. The technical implementation involves the feed preview feature not properly sanitizing or isolating external content, enabling attackers to craft feed entries that when previewed trigger unintended JavaScript execution. This flaw directly maps to CWE-20, which describes improper input validation, and specifically relates to privilege escalation through improper access control mechanisms. The operational impact is severe as attackers can leverage this vulnerability to execute arbitrary code with chrome privileges, potentially allowing them to access sensitive browser data, manipulate browser functionality, or perform actions that should be restricted to the browser's core components. This vulnerability aligns with ATT&CK technique T1059.007 for JavaScript execution and T1548.002 for privilege escalation through browser components. The risk is particularly elevated because feed preview functionality is commonly used by users and the attack can be delivered through seemingly benign RSS or Atom feed content. Attackers can craft malicious feed entries that when processed by the feed preview feature execute JavaScript code with elevated privileges, effectively bypassing the browser's security model. The vulnerability demonstrates a failure in the principle of least privilege, where feed preview processing does not adequately separate user content from privileged browser operations. Organizations using affected Firefox versions face significant risk as this vulnerability can be exploited through social engineering campaigns targeting users with malicious feeds or through compromised feed sources. The exploitability of this vulnerability is high due to the common use of feed preview functionality and the relatively simple nature of crafting malicious feed content that triggers the privilege escalation. This flaw underscores the importance of proper input sanitization and privilege separation in browser security implementations, particularly for features that process external content. The remediation involves updating to Firefox 2.0.0.19 or later versions where the feed preview functionality has been properly secured to prevent unauthorized privilege escalation through feed processing. Security teams should implement network monitoring to detect suspicious feed content and ensure timely patch deployment to protect against exploitation attempts.