CVE-2016-5221 in Chrome
Summary
by MITRE
Type confusion in libGLESv2 in ANGLE in Google Chrome prior to 55.0.2883.75 for Mac, Windows and Linux, and 55.0.2883.84 for Android possibly allowed a remote attacker to bypass buffer validation via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability CVE-2016-5221 represents a critical type confusion issue within the ANGLE graphics library component of Google Chrome browsers across multiple platforms. This flaw exists in the libGLESv2 implementation that handles OpenGL ES graphics operations, specifically affecting Chrome versions prior to 55.0.2883.75 on Mac, Windows, and Linux platforms, and 55.0.2883.84 on Android devices. The vulnerability stems from improper handling of data types during graphics rendering operations, creating a scenario where the system incorrectly interprets the type of data being processed.
The technical root cause of this vulnerability aligns with CWE-466, which describes the improper handling of type confusion in programming environments. The flaw manifests when Chrome processes specially crafted HTML pages that contain malicious graphics commands designed to exploit the type confusion in the ANGLE library's graphics processing pipeline. During normal operation, the graphics subsystem expects specific data types to be passed to various rendering functions, but the vulnerability allows attackers to manipulate the data flow to pass incorrect types, causing the system to execute unintended code paths.
From an operational perspective, this vulnerability presents a significant remote code execution risk that can be exploited through web-based attacks. Attackers can craft malicious HTML pages that when loaded in affected Chrome versions trigger the type confusion error, potentially allowing them to execute arbitrary code with the privileges of the browser process. The impact extends beyond simple browser compromise as successful exploitation could lead to full system compromise, particularly given that Chrome's graphics rendering subsystem operates with elevated privileges to access hardware acceleration features. This vulnerability affects all supported platforms where Chrome utilizes the ANGLE graphics library, making it a widespread concern for organizations relying on Chrome-based browsing environments.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1059.007, which involves the use of scripting languages for execution, and T1203, which covers legitimate user execution paths for malicious code. The attack vector typically involves phishing emails, malicious websites, or compromised web applications that serve the crafted HTML content. Organizations should implement immediate mitigations including mandatory browser updates to versions 55.0.2883.75 or later for Mac, Windows, and Linux, and 55.0.2883.84 for Android. Additional protective measures include implementing web application firewalls, restricting access to potentially malicious websites, and deploying browser hardening configurations that disable unnecessary graphics features. Security teams should also monitor for indicators of compromise related to this vulnerability and ensure that all endpoints are regularly updated to prevent exploitation attempts. The vulnerability highlights the importance of proper input validation and type checking in graphics libraries, emphasizing that even seemingly benign rendering operations can become attack vectors when proper type safety mechanisms are not implemented.