CVE-2013-0747 in Firefox
Summary
by MITRE
The gPluginHandler.handleEvent function in the plugin handler in Mozilla Firefox before 18.0, Firefox ESR 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderbird ESR 17.x before 17.0.2, and SeaMonkey before 2.15 does not properly enforce the Same Origin Policy, which allows remote attackers to conduct clickjacking attacks via crafted JavaScript code that listens for a mutation event.
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Analysis
by VulDB Data Team • 04/20/2021
The vulnerability described in CVE-2013-0747 represents a critical security flaw in Mozilla Firefox and related applications that stems from improper enforcement of the Same Origin Policy within the plugin handler component. This weakness affects multiple Mozilla products including Firefox versions prior to 18.0, Thunderbird versions before 17.0.2, and SeaMonkey versions before 2.15, creating a persistent security risk across the Mozilla ecosystem. The vulnerability specifically resides in the gPluginHandler.handleEvent function which fails to adequately validate cross-origin requests when processing plugin events, allowing malicious actors to exploit this gap in security enforcement.
The technical implementation of this vulnerability enables remote attackers to execute sophisticated clickjacking attacks through carefully crafted JavaScript code that monitors mutation events. This flaw operates at the intersection of browser security mechanisms and plugin handling, where the plugin handler component should enforce strict origin-based access controls but instead permits unauthorized cross-origin interactions. The mutation event listening capability provides attackers with a mechanism to detect and manipulate plugin behaviors across different origins, effectively bypassing the browser's fundamental security boundary enforcement. This represents a classic example of a privilege escalation vulnerability where a component that should maintain strict isolation fails to enforce proper access controls.
The operational impact of this vulnerability extends beyond simple clickjacking scenarios to encompass broader security implications for users of affected Mozilla applications. Attackers can leverage this weakness to construct deceptive user interfaces that trick users into performing unintended actions while maintaining the appearance of legitimate application behavior. The vulnerability particularly affects web applications that rely on plugin interactions, making it especially dangerous in environments where users frequently interact with rich web content. The exploitation requires minimal user interaction beyond visiting a malicious website, making it particularly effective for social engineering campaigns that target unsuspecting users. This vulnerability undermines the core security model of modern web browsers by allowing unauthorized cross-origin plugin manipulation.
Mitigation strategies for CVE-2013-0747 require immediate application of security patches to all affected versions of Mozilla Firefox, Thunderbird, and SeaMonkey. Organizations should prioritize updating to the patched versions where Firefox 18.0, Thunderbird 17.0.2, and SeaMonkey 2.15 provide the necessary fixes. Additionally, administrators should implement network-level monitoring to detect potential exploitation attempts and consider deploying content security policies to limit plugin interactions. The vulnerability aligns with CWE-346, which addresses improper verification of data integrity, and maps to ATT&CK technique T1211 for privilege escalation through browser components. Security teams should also consider implementing browser hardening measures including disabling unnecessary plugin functionality and monitoring for suspicious mutation event handling patterns in user sessions. Regular security assessments should verify that plugin handler components properly enforce same origin policies and that no unauthorized cross-origin access occurs during plugin interactions.