CVE-2016-3392 in Edge
Summary
by MITRE
The Edge Content Security Policy feature in Microsoft Edge does not properly validate documents, which allows remote attackers to bypass intended access restrictions via a crafted web site, aka "Microsoft Browser Security Feature Bypass Vulnerability."
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Analysis
by VulDB Data Team • 09/23/2022
The vulnerability identified as CVE-2016-3392 represents a critical security flaw within Microsoft Edge's Content Security Policy implementation that undermines the browser's core security mechanisms. This weakness specifically targets the Edge browser's ability to enforce access restrictions on web content, creating a pathway for malicious actors to circumvent intended security controls. The issue stems from insufficient validation processes that govern how Edge processes and evaluates web documents, allowing attackers to craft specific web pages that can bypass the browser's security policies.
The technical flaw manifests in Edge's Content Security Policy enforcement system where the browser fails to properly validate the integrity and source of web documents before permitting access to restricted resources. This validation failure occurs during the document processing phase where Edge should verify that content adheres to established security boundaries but instead accepts malformed or crafted documents that contain embedded malicious code or references. The vulnerability operates at the intersection of web security policy enforcement and document parsing, creating a gap where attackers can exploit the browser's trust model to access restricted content or execute unauthorized operations.
Operationally, this vulnerability presents significant risks to users of Microsoft Edge as it allows remote attackers to bypass security controls that are fundamental to protecting against cross-site scripting attacks, data theft, and privilege escalation. An attacker could craft a malicious website that appears legitimate but contains carefully constructed content designed to exploit the validation gap in Edge's Content Security Policy implementation. This could enable unauthorized access to sensitive data, session hijacking, or the execution of arbitrary code within the browser context. The remote nature of the attack means users can be compromised simply by visiting a malicious website, making this vulnerability particularly dangerous in phishing campaigns or drive-by download scenarios.
The impact of CVE-2016-3392 aligns with CWE-284, which addresses improper access control in software systems, and can be categorized under ATT&CK technique T1059 for execution through web-based attacks. Organizations using Microsoft Edge are particularly vulnerable as this flaw affects the browser's core security architecture, potentially allowing attackers to bypass multiple layers of security that should protect users from malicious content. The vulnerability also relates to broader web security principles outlined in OWASP Top 10, specifically addressing issues around insecure content handling and inadequate input validation that can lead to security policy circumvention.
Mitigation strategies for this vulnerability should include immediate deployment of Microsoft security updates and patches that address the Content Security Policy validation flaw. Organizations should also implement additional network-level protections such as web application firewalls and content filtering solutions that can detect and block malicious web content before it reaches user browsers. Browser hardening measures including disabling unnecessary features and implementing strict security policies can further reduce the attack surface. Users should be educated about the risks of visiting untrusted websites and the importance of keeping their browsers updated. The vulnerability demonstrates the critical importance of proper input validation and security policy enforcement in browser security architectures, highlighting that even fundamental security features can be compromised when validation mechanisms are insufficiently implemented.