CVE-2009-2472 in Firefox
Summary
by MITRE
Mozilla Firefox before 3.0.12 does not always use XPCCrossOriginWrapper when required during object construction, which allows remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via a crafted document, related to a "cross origin wrapper bypass."
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Analysis
by VulDB Data Team • 08/12/2021
The vulnerability identified as CVE-2009-2472 represents a critical security flaw in Mozilla Firefox versions prior to 3.0.12 that fundamentally undermines the browser's core security mechanism known as the Same Origin Policy. This policy serves as the cornerstone of web security by preventing scripts from one origin from accessing resources or data from another origin, thereby protecting users from malicious cross-site attacks. The flaw specifically manifests during object construction processes where Firefox fails to consistently employ XPCCrossOriginWrapper, a security component designed to enforce cross-origin access restrictions.
The technical implementation of this vulnerability stems from Firefox's insufficient enforcement of cross-origin wrappers during JavaScript object creation and manipulation. When a web page attempts to access properties or methods of objects from different origins, the browser should utilize XPCCrossOriginWrapper to mediate these access attempts and ensure proper security boundaries are maintained. However, in affected versions, this wrapper mechanism was not consistently invoked, creating a scenario where malicious actors could craft specially designed documents that exploit this inconsistency to bypass normal security checks. The vulnerability operates at the intersection of browser security architecture and JavaScript execution environments, leveraging weaknesses in the object model's cross-origin handling mechanisms.
The operational impact of this vulnerability extends far beyond simple bypass of security restrictions, as it enables sophisticated cross-site scripting attacks that can compromise user sessions and data integrity. Attackers can construct malicious web pages that appear benign but contain code designed to exploit the wrapper bypass, allowing them to access sensitive information from other domains, manipulate objects across origin boundaries, and potentially execute arbitrary code within the victim's browser context. This represents a significant threat to web application security and user privacy, as it undermines the fundamental isolation guarantees that web browsers provide between different websites and their respective data stores. The vulnerability's exploitation requires minimal user interaction beyond visiting a malicious website, making it particularly dangerous in phishing campaigns and drive-by download scenarios.
Mitigation strategies for CVE-2009-2472 primarily focus on immediate browser updates to versions 3.0.12 or later where the cross-origin wrapper enforcement has been properly implemented and tested. Organizations should also implement comprehensive web application firewalls and content security policies to add additional layers of protection against exploitation attempts. The vulnerability aligns with CWE-284 Access Control Issues and maps to ATT&CK technique T1059 Command and Scripting Interpreter, specifically targeting the execution of malicious scripts in compromised browser environments. Security administrators should also consider implementing browser hardening measures such as disabling unnecessary JavaScript features, restricting cross-origin resource sharing, and maintaining regular security audits to identify potential exploitation vectors. Additionally, user education regarding suspicious website behavior and the importance of keeping browser software updated remains crucial in defending against such attacks that exploit implementation gaps in security frameworks.