CVE-2016-5132 in Chrome
Summary
by MITRE
The Service Workers subsystem in Google Chrome before 52.0.2743.82 does not properly implement the Secure Contexts specification during decisions about whether to control a subframe, which allows remote attackers to bypass the Same Origin Policy via an https IFRAME element inside an http IFRAME element.
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Analysis
by VulDB Data Team • 09/09/2022
The vulnerability CVE-2016-5132 represents a critical security flaw in Google Chrome's Service Workers implementation that fundamentally undermines the browser's security model. This issue exists within the Secure Contexts specification implementation, which is designed to ensure that certain powerful web APIs can only be accessed from secure origins. The flaw specifically affects Chrome versions prior to 52.0.2743.82, creating a dangerous gap in the browser's ability to enforce security boundaries between different execution contexts.
The technical implementation flaw occurs when Chrome evaluates whether a Service Worker should control a subframe, particularly when dealing with nested iframe structures. In this scenario, an attacker can exploit the improper handling of secure context decisions by placing an https iframe inside an http iframe, effectively bypassing the Same Origin Policy that normally protects against cross-origin attacks. This misimplementation allows malicious content within the http context to gain unauthorized access to resources and functionality that should only be available within secure contexts.
The operational impact of this vulnerability is severe as it enables attackers to perform cross-origin information disclosure and potentially execute arbitrary code within contexts where such access should be strictly prohibited. Attackers can leverage this flaw to bypass security restrictions that normally prevent http pages from accessing powerful APIs like Service Workers, which can lead to session hijacking, data theft, and other malicious activities. The vulnerability essentially creates a backdoor that allows untrusted http content to manipulate trusted https content through the iframe nesting mechanism.
This vulnerability aligns with CWE-284, which addresses improper access control issues, and maps to ATT&CK technique T1059.001 for command and scripting interpreter usage. The flaw demonstrates how improper implementation of security specifications can create exploitable conditions that bypass fundamental web security models. Organizations should immediately update to Chrome 52.0.2743.82 or later to remediate this vulnerability, as the fix properly implements the Secure Contexts specification and ensures that Service Worker control decisions correctly account for the security context of nested iframes. The vulnerability highlights the importance of rigorous implementation of security specifications and the potential consequences of incomplete security model enforcement in web browsers.