CVE-2012-0958 in unity-firefox-extension
Summary
by MITRE
content/unity-api.js in the unity-firefox-extension extension 2.4.1 for Firefox exposes the toDataURL function in an API call, which allows remote attackers to bypass the Same Origin Policy and obtain sensitive information via a crafted webpage.
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Analysis
by VulDB Data Team • 12/21/2021
The vulnerability described in CVE-2012-0958 represents a critical security flaw within the unity-firefox-extension version 2.4.1 for Firefox browser. This extension, designed to integrate Unity web content with Firefox, contained a dangerous API exposure that fundamentally compromised the browser's security model. The flaw specifically resides in the content/unity-api.js file where the toDataURL function is improperly exposed through an API call, creating an avenue for malicious actors to exploit the extension's functionality.
The technical implementation of this vulnerability stems from the improper handling of cross-origin resource access within the Firefox extension environment. The toDataURL function, when exposed through the unity-api.js interface, allows remote attackers to craft malicious webpages that can access data from other origins that would normally be restricted by the Same Origin Policy. This policy enforcement mechanism is fundamental to web security, preventing unauthorized access to resources across different domains. The exposure of this function essentially creates a backdoor that bypasses these critical security boundaries, enabling attackers to extract sensitive information from within the browser's security context.
From an operational impact perspective, this vulnerability poses significant risks to users of the affected Firefox extension. Attackers can leverage this flaw to perform cross-site scripting attacks, data exfiltration, and potentially gain access to user credentials or other sensitive information stored in the browser environment. The vulnerability is particularly dangerous because it operates at the extension level, which typically has elevated privileges and access to user data that regular web pages cannot access. This creates a scenario where malicious websites can exploit the extension's functionality to circumvent standard browser security measures and access resources that should remain protected.
The security implications of this vulnerability align with CWE-284, which addresses improper access control in software systems, and can be mapped to ATT&CK technique T1059 for executing malicious code through browser extensions. The flaw demonstrates a classic case of insufficient input validation and improper privilege management in browser extension development, where API functions intended for internal use were exposed without proper access controls. Organizations using Firefox with this extension would be vulnerable to attacks that could compromise user data and system integrity.
Mitigation strategies for this vulnerability should focus on immediate extension updates to versions that properly implement access controls and remove the exposed API functions. Users should be advised to disable or uninstall the vulnerable extension until proper patches are applied. Additionally, browser administrators should implement strict extension management policies and consider using security tools to monitor for unauthorized API access patterns. The recommended approach includes deploying web application firewalls that can detect and block malicious requests attempting to exploit this specific API exposure, along with regular security audits of browser extensions to identify similar privilege escalation vulnerabilities.