CVE-2020-6552 in Chrome
Summary
by MITRE
Use after free in Blink in Google Chrome prior to 84.0.4147.125 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/05/2025
The vulnerability CVE-2020-6552 represents a critical use-after-free flaw in the Blink rendering engine component of Google Chrome browsers. This issue affected versions prior to 84.0.4147.125 and exposed users to potential remote code execution risks through maliciously crafted web pages. The vulnerability stems from improper memory management within the browser's rendering pipeline where freed memory blocks are accessed after being deallocated, creating opportunities for attackers to manipulate heap structures and potentially execute arbitrary code.
The technical nature of this flaw aligns with CWE-416, which specifically addresses use-after-free conditions in software systems. In the context of web browsers, such vulnerabilities occur when the rendering engine fails to properly track object lifecycles and memory references. When a web page contains maliciously constructed html elements or javascript code that triggers specific rendering paths, the Blink engine may free memory associated with certain objects while other code paths still reference those locations. This creates a window where attacker-controlled data can be written to the freed memory region, leading to heap corruption that can be exploited to gain control over the browser process.
From an operational perspective, this vulnerability presents significant risk to users who browse the internet without proper security measures. The remote exploitation capability means that simply visiting a malicious website could result in compromise without any user interaction beyond normal browsing behavior. Attackers could craft html pages that trigger specific memory allocation patterns and subsequent deallocations, creating conditions where controlled data can overwrite freed memory locations. The heap corruption resulting from this flaw could enable attackers to execute code with the privileges of the browser process, potentially leading to full system compromise depending on the underlying operating system and user permissions.
The impact of CVE-2020-6552 extends beyond immediate exploitation as it represents a fundamental memory safety issue that can be leveraged for various attack vectors. According to ATT&CK framework, this vulnerability maps to techniques involving memory corruption and code execution within browser environments. The remediation strategy centers on updating to Chrome version 84.0.4147.125 or later, which includes patches addressing the memory management issues in Blink's rendering engine. Organizations should implement immediate patch management protocols to mitigate this risk, as the vulnerability exists in widely used browser versions that remain prevalent across enterprise and consumer environments. Additional protective measures include implementing content security policies, using sandboxing features, and maintaining up-to-date browser security configurations to reduce the attack surface and limit potential exploitation success rates.