CVE-2013-0794 in Firefox
Summary
by MITRE
Mozilla Firefox before 20.0 and SeaMonkey before 2.17 do not prevent origin spoofing of tab-modal dialogs, which allows remote attackers to conduct phishing attacks via a crafted web site.
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Analysis
by VulDB Data Team • 04/26/2017
The vulnerability identified as CVE-2013-0794 represents a critical security flaw in Mozilla Firefox versions prior to 20.0 and SeaMonkey versions prior to 2.17 that undermines the browser's ability to properly validate dialog origins. This issue specifically affects tab-modal dialogs which are user interface elements designed to provide contextual information or prompts within specific browser tabs. The flaw enables malicious actors to exploit the browser's origin validation mechanisms, creating a dangerous condition where users cannot reliably distinguish between legitimate browser prompts and fraudulent ones generated by malicious websites.
The technical implementation of this vulnerability stems from insufficient validation of the origin field in tab-modal dialog interfaces. When browsers display modal dialogs, they typically verify the source of the prompt to ensure it originates from the expected domain or browser component. However, in affected versions of Firefox and SeaMonkey, this validation process was compromised, allowing attackers to manipulate the displayed origin information. This manipulation occurs through JavaScript execution within malicious web pages that can programmatically control dialog properties, effectively spoofing the origin of the dialog to appear as if it originates from a trusted source rather than the actual website or browser component.
The operational impact of this vulnerability is significant and directly enables sophisticated phishing attacks that can deceive even security-conscious users. Attackers can craft malicious websites that display tab-modal dialogs claiming to be from legitimate services such as banking applications, social media platforms, or browser security warnings. Users interacting with these deceptive dialogs may unknowingly provide sensitive information including passwords, credit card numbers, or personal identification details. The vulnerability particularly affects user trust models since the browser's own security warnings and prompts are being manipulated, making it difficult for users to differentiate between genuine browser security alerts and maliciously crafted impostors. This exploitation technique leverages the inherent trust users place in browser interface elements, effectively bypassing traditional security measures that rely on user recognition of legitimate security prompts.
This vulnerability aligns with CWE-602, which addresses client-side input validation that relies on server-side validation, and represents a specific instance of user interface spoofing that can be categorized under the ATT&CK technique T1566 for Phishing. The flaw demonstrates how browser interface elements can be manipulated to create false impressions of trustworthiness, making it particularly dangerous in enterprise environments where users may be targeted with sophisticated social engineering campaigns. Organizations should implement immediate mitigation strategies including mandatory browser updates to versions 20.0 or later for Firefox and 2.17 or later for SeaMonkey, alongside user education about the importance of verifying origin information in browser dialogs. Network-level defenses should also monitor for suspicious web content that attempts to manipulate dialog origins, while security teams should conduct regular vulnerability assessments to identify similar interface manipulation vulnerabilities that could compromise user trust and security posture.