CVE-2012-3980 in Firefox
Summary
by MITRE
The web console in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, and Thunderbird ESR 10.x before 10.0.7 allows user-assisted remote attackers to execute arbitrary JavaScript code with chrome privileges via a crafted web site that injects this code and triggers an eval operation.
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Analysis
by VulDB Data Team • 12/31/2024
The vulnerability described in CVE-2012-3980 represents a critical security flaw in Mozilla Firefox and Thunderbird web browsers that existed prior to specific version releases. This issue resides within the web console functionality of these applications, which serves as a debugging and development tool that allows users to execute JavaScript code in the browser environment. The vulnerability specifically targets the chrome privileges system, which grants elevated access to browser internals and system resources that normal web pages should not be able to access. When a malicious website crafts a specific payload that exploits this flaw, it can inject JavaScript code that executes with chrome privileges, effectively bypassing the normal security boundaries that separate user content from browser core functionality.
The technical mechanism behind this vulnerability involves the improper handling of eval operations within the browser's web console implementation. When a crafted website triggers an eval operation through the web console, the browser fails to properly validate or sanitize the input before executing the JavaScript code with elevated privileges. This creates a privilege escalation scenario where untrusted web content can gain access to chrome-level functionality that should only be available to the browser's own internal processes. The vulnerability is classified as user-assisted because it requires the victim to interact with a malicious website, typically by visiting it or clicking on a link that triggers the exploit. The flaw demonstrates a failure in the browser's privilege separation model, which is a fundamental security principle that prevents malicious code from accessing sensitive system resources.
The operational impact of this vulnerability is severe and far-reaching, as it enables attackers to execute arbitrary code with the highest level of privileges available to the browser application. This means that malicious actors could potentially access user data, modify browser settings, install malware, or even gain access to the underlying operating system resources depending on the browser's security model. The vulnerability affects not just Firefox but also Thunderbird, indicating a widespread issue within Mozilla's browser architecture that could compromise user security across multiple applications. The attack vector through crafted websites means that users could be exploited simply by visiting compromised sites, making it particularly dangerous in environments where users might encounter malicious content. According to CWE standards, this vulnerability maps to CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and specifically relates to the improper handling of code execution in privileged contexts.
The exploitation of this vulnerability aligns with several techniques documented in the MITRE ATT&CK framework, particularly in the area of privilege escalation and code injection. Attackers could leverage this flaw to move laterally within a user's browser environment and potentially escalate their access to system-level operations. The vulnerability also demonstrates weaknesses in input validation and privilege management that are commonly targeted in advanced persistent threat campaigns. Organizations using affected versions of Firefox or Thunderbird face significant risk of data breaches and system compromise, as this vulnerability could enable attackers to bypass traditional security controls that rely on browser sandboxing and privilege separation. The fix for this vulnerability required Mozilla to implement proper input sanitization and privilege validation within the web console's eval handling mechanism, ensuring that code execution occurs within appropriate security boundaries. This remediation approach addresses the root cause by enforcing strict separation between user-provided content and chrome-level operations, thereby preventing unauthorized privilege escalation through malicious code injection.