CVE-2018-6034 in Chrome
Summary
by MITRE
Insufficient data validation in WebGL in Google Chrome prior to 64.0.3282.119 allowed a remote attacker to perform an out of bounds memory read via a crafted HTML page.
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Analysis
by VulDB Data Team • 02/03/2023
The vulnerability identified as CVE-2018-6034 represents a critical security flaw in Google Chrome's WebGL implementation that existed prior to version 64.0.3282.119. This issue stems from inadequate input validation mechanisms within the WebGL graphics rendering subsystem, which processes and executes graphics commands from web pages. The flaw specifically manifests as an insufficient data validation condition that allows malicious actors to manipulate WebGL operations through carefully crafted HTML content, ultimately enabling unauthorized memory access patterns.
WebGL (Web Graphics Library) is a JavaScript API that enables rendering interactive 2D and 3D graphics within web browsers without requiring additional plugins or extensions. It provides direct access to graphics processing unit capabilities through OpenGL ES APIs, making it a powerful but potentially dangerous component when security controls are inadequate. The vulnerability occurs when Chrome processes WebGL commands from untrusted web content, particularly when handling array bounds checking during graphics operations. Attackers can exploit this weakness by creating malicious HTML pages that contain specially constructed WebGL commands designed to trigger memory read operations beyond allocated buffer boundaries.
The operational impact of this vulnerability is significant as it allows remote attackers to perform out-of-bounds memory reads, which can potentially expose sensitive information stored in memory. This type of vulnerability falls under the CWE-129 category of "Improper Validation of Array Index" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript." When exploited, the vulnerability could enable attackers to extract memory contents that might include cryptographic keys, user credentials, or other confidential data. The attack vector requires only a user to visit a malicious webpage, making it particularly dangerous for widespread exploitation in phishing campaigns or drive-by download scenarios.
The technical exploitation of this vulnerability demonstrates how WebGL's graphics command processing can be manipulated to bypass normal memory safety mechanisms. The flaw likely occurs in the WebGL implementation's handling of vertex buffer objects or similar graphics data structures where array bounds checking is insufficient. This allows attackers to craft WebGL commands that reference memory locations outside the intended buffer boundaries, potentially reading adjacent memory contents. Such memory disclosure vulnerabilities are particularly concerning as they can provide attackers with information that may be used to further compromise systems or aid in developing more sophisticated attacks. The vulnerability highlights the importance of proper input validation and bounds checking in graphics APIs and reinforces the need for comprehensive security testing of browser graphics subsystems. Organizations should prioritize updating to Chrome version 64.0.3282.119 or later to mitigate this risk, as the fix would include enhanced validation mechanisms for WebGL operations and improved memory access controls.