CVE-2009-3374 in Firefox
Summary
by MITRE
The XPCVariant::VariantDataToJS function in the XPCOM implementation in Mozilla Firefox 3.0.x before 3.0.15 and 3.5.x before 3.5.4 does not enforce intended restrictions on interaction between chrome privileged code and objects obtained from remote web sites, which allows remote attackers to execute arbitrary JavaScript with chrome privileges via unspecified method calls, related to "doubly-wrapped objects."
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/24/2021
The vulnerability described in CVE-2009-3374 represents a critical security flaw in Mozilla Firefox's cross-platform component object model implementation that enabled privilege escalation attacks. This issue specifically affects Firefox versions 3.0.x prior to 3.0.15 and 3.5.x prior to 3.5.4, where the XPCVariant::VariantDataToJS function failed to properly enforce security boundaries between privileged chrome code and untrusted content from remote web sites. The flaw stems from inadequate validation of object interactions within the XPCOM (Cross-Platform Component Object Model) framework, which serves as Firefox's core component architecture for managing communication between different parts of the browser.
The technical root cause of this vulnerability lies in the improper handling of doubly-wrapped objects within Firefox's security model. When chrome privileged code attempted to interact with objects obtained from remote web sites, the XPCVariant::VariantDataToJS function did not adequately restrict the types of method calls that could be executed. This created a scenario where remote attackers could craft malicious JavaScript code that, when executed in the context of a web page, could manipulate the browser's internal object model to gain access to chrome privileges. The vulnerability specifically exploited the way Firefox handled object wrapping and unwrapping operations, allowing attackers to bypass security restrictions that normally prevent untrusted code from executing with elevated privileges.
The operational impact of this vulnerability is severe as it enables remote code execution with the highest privileges available within the browser environment. Attackers could leverage this flaw to execute arbitrary JavaScript code with chrome privileges, effectively allowing them to perform actions such as accessing local files, modifying browser settings, reading sensitive data, or even installing malicious software on the victim's system. The attack vector involves delivering malicious content through web pages that trigger the vulnerable code path, making this a significant threat for phishing attacks and drive-by downloads. This vulnerability essentially undermines the fundamental security model of Firefox by allowing untrusted web content to escalate privileges and gain access to the browser's most privileged operations.
The vulnerability aligns with CWE-284, which describes improper access control in software systems, and demonstrates how inadequate privilege separation in component models can lead to severe security consequences. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and code injection, specifically targeting the browser's security boundaries and component interaction mechanisms. Organizations should implement immediate mitigations including upgrading to Firefox versions 3.0.15 or 3.5.4, which contain the necessary patches to address the object wrapping and unwrapping issues. Additionally, administrators should consider implementing network-level protections such as content filtering and web application firewalls to reduce the risk of exploitation, while security teams should monitor for indicators of compromise related to this vulnerability in their environments.
The patch for this vulnerability specifically addresses the XPCVariant::VariantDataToJS function by implementing stricter validation of object interactions between chrome privileged code and remote content. This fix ensures that doubly-wrapped objects cannot be used to bypass security restrictions, thereby preventing the escalation of privileges that would otherwise be possible through the flawed object handling mechanism. The resolution demonstrates the importance of maintaining strict security boundaries in complex software architectures and highlights how seemingly minor flaws in component interaction can have significant security implications for entire browser ecosystems.