CVE-2015-6755 in Chrome
Summary
by MITRE
The ContainerNode::parserInsertBefore function in core/dom/ContainerNode.cpp in Blink, as used in Google Chrome before 46.0.2490.71, proceeds with a DOM tree insertion in certain cases where a parent node no longer contains a child node, which allows remote attackers to bypass the Same Origin Policy via crafted JavaScript code.
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Analysis
by VulDB Data Team • 06/21/2022
The vulnerability identified as CVE-2015-6755 resides within the Blink rendering engine's DOM manipulation logic, specifically in the ContainerNode::parserInsertBefore function located in core/dom/ContainerNode.cpp. This flaw represents a critical security issue that undermines the fundamental web security model by enabling unauthorized access to cross-origin resources. The vulnerability affects Google Chrome versions prior to 46.0.2490.71, making it a significant concern for users operating older browser versions.
The technical implementation of this vulnerability stems from improper validation of DOM node relationships during insertion operations. When the parserInsertBefore function processes DOM tree modifications, it fails to properly verify that the parent node still contains the specified child node before proceeding with the insertion. This condition creates a race scenario where malicious JavaScript code can manipulate the DOM structure in such a way that the function continues processing even when the expected parent-child relationship no longer exists. The flaw essentially allows for a form of DOM manipulation that bypasses normal security boundaries.
From an operational perspective, this vulnerability enables remote attackers to circumvent the Same Origin Policy, which is a fundamental security mechanism that prevents scripts from one origin from accessing resources from another origin. The exploitation occurs through carefully crafted JavaScript code that manipulates DOM nodes in a manner that triggers the flawed insertion logic. This capability allows attackers to potentially access sensitive information, perform cross-origin data theft, or execute unauthorized operations that should be restricted by browser security policies. The impact extends beyond simple information disclosure to potentially enable more sophisticated attacks that leverage the bypassed security controls.
The vulnerability aligns with CWE-119, which addresses improper access to memory, and can be mapped to ATT&CK technique T1059.007 for JavaScript execution and T1071.001 for application layer protocol usage. This mapping reflects how the vulnerability enables malicious code execution through legitimate browser interfaces while exploiting memory access patterns that should be protected by security boundaries. The flaw demonstrates a classic case of insufficient input validation and improper state management during DOM operations. Organizations should prioritize updating to Chrome version 46.0.2490.71 or later to remediate this vulnerability, as the patch addresses the core logic error in the DOM insertion validation mechanism. Additionally, administrators should monitor for any exploitation attempts through network traffic analysis and implement appropriate web application firewall rules to detect and block suspicious DOM manipulation patterns that could indicate exploitation attempts.