CVE-2020-6523 in Chrome
Summary
by MITRE
Out of bounds write in Skia in Google Chrome prior to 84.0.4147.89 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 identified as CVE-2020-6523 represents a critical out-of-bounds write flaw within the Skia graphics rendering library that forms a core component of Google Chrome's rendering engine. This issue affects Chrome versions prior to 84.0.4147.89 and demonstrates how graphics processing components can serve as prime targets for remote code execution attacks. The flaw exists in the Skia graphics library's handling of certain HTML page elements, specifically when processing malformed or crafted graphics data that exceeds allocated memory boundaries during rendering operations.
The technical nature of this vulnerability stems from improper bounds checking within Skia's memory allocation and manipulation routines. When Chrome processes HTML content containing maliciously crafted graphics elements, the rendering engine fails to validate array indices or buffer sizes before writing data to memory locations. This memory corruption occurs during the rasterization process where graphics primitives are converted into pixel data for display. The out-of-bounds write condition allows an attacker to overwrite adjacent memory regions, potentially corrupting critical data structures or executable code within the browser's memory space. This type of vulnerability aligns with CWE-787, which specifically addresses out-of-bounds writes in software systems.
From an operational perspective, this vulnerability enables remote attackers to achieve arbitrary code execution on targeted systems through carefully constructed web pages. The attack vector requires the victim to visit a malicious website or be tricked into viewing crafted HTML content, making it particularly dangerous in phishing campaigns or drive-by download scenarios. Successful exploitation can lead to full system compromise, allowing attackers to execute commands with the privileges of the browser process, potentially escalating to system-level access. The vulnerability's remote exploitability means that attackers do not require physical access to the target system and can leverage web-based delivery mechanisms to compromise users.
Security researchers have classified this issue as particularly concerning due to its potential for widespread exploitation within the Chrome browser ecosystem, which serves as the default browser for billions of users globally. The remediation strategy involves updating to Chrome version 84.0.4147.89 or later, which includes patches addressing the bounds checking deficiencies in Skia's memory handling routines. Organizations should prioritize immediate deployment of this security update across all affected systems and implement additional security measures such as web application firewalls and browser hardening configurations. The vulnerability also highlights the importance of maintaining up-to-date graphics libraries and implementing robust memory safety practices in browser rendering engines, as referenced in various ATT&CK framework techniques related to privilege escalation and code execution through browser vulnerabilities.