CVE-2021-30604 in Chrome
Summary
by MITRE • 08/27/2021
Use after free in ANGLE in Google Chrome prior to 92.0.4515.159 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/25/2026
This vulnerability represents a critical use-after-free condition in the ANGLE graphics library component that forms part of Google Chrome's rendering engine. The flaw exists within the handling of graphics resources during WebGL operations, where improper memory management allows attackers to manipulate freed memory locations. The vulnerability is classified under CWE-416 which specifically addresses use-after-free errors, making it a well-documented and dangerous class of memory safety issue. When a web page containing maliciously crafted HTML elements is loaded, the browser's graphics processing subsystem executes code that triggers the use-after-free scenario, potentially leading to arbitrary code execution in the browser context. The attack vector requires a remote attacker to deliver a specially crafted webpage that leverages WebGL APIs to manipulate graphics objects, causing the ANGLE library to free memory resources while still referenced elsewhere in the system. This creates an opportunity for memory corruption that can be exploited to execute malicious code with the privileges of the browser process, bypassing typical security boundaries.
The operational impact of this vulnerability extends beyond simple memory corruption as it enables sophisticated attack techniques that align with ATT&CK framework tactics including privilege escalation and code execution. Attackers can leverage the heap corruption to overwrite critical function pointers or control structures within the ANGLE library, potentially redirecting execution flow to malicious payloads. The vulnerability's exploitation requires a combination of precise memory manipulation and browser-specific conditions that make it particularly challenging to defend against using traditional sandboxing approaches. The specific nature of the flaw means that the attack surface is limited to WebGL operations but remains highly impactful due to the privileged execution context of graphics processing components. This vulnerability demonstrates the inherent risks in complex graphics libraries that operate outside the typical browser sandbox boundaries, where memory management errors can have severe consequences for overall system security.
Mitigation strategies for this vulnerability must address both the immediate remediation through software updates and longer-term architectural improvements in graphics library design. Organizations should prioritize immediate patching of Chrome installations to versions 92.0.4515.159 or later where the use-after-free has been resolved through proper memory management fixes. The underlying fix involves implementing proper reference counting and object lifecycle management within the ANGLE component to prevent freed memory from being accessed after deallocation. Security teams should also consider implementing network-level protections such as content security policies that restrict WebGL usage in sensitive environments, though this approach has limitations as the vulnerability can be triggered through legitimate web content. Additional defensive measures include monitoring for anomalous graphics processing patterns and implementing exploit detection systems that can identify attempts to manipulate freed memory structures. The vulnerability highlights the importance of regular security assessments of graphics libraries and the need for more rigorous memory safety testing in browser components that handle untrusted input. Organizations should also consider implementing browser hardening measures that limit the capabilities of graphics processing components and reduce the potential impact of similar vulnerabilities in the future.