CVE-2021-30579 in Chrome
Summary
by MITRE • 08/04/2021
Use after free in UI framework in Google Chrome prior to 92.0.4515.107 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 08/07/2021
The vulnerability identified as CVE-2021-30579 represents a critical use-after-free condition within the user interface framework of Google Chrome browser. This flaw exists in versions prior to 92.0.4515.107 and enables remote attackers to potentially exploit heap corruption through maliciously crafted HTML pages. The issue stems from improper memory management practices where freed memory blocks are still accessed by the application, creating opportunities for arbitrary code execution. Such vulnerabilities are particularly dangerous as they can be triggered remotely without user interaction, making them prime targets for exploitation in zero-day attacks.
The technical implementation of this vulnerability involves the browser's UI framework failing to properly manage object lifecycles during HTML page rendering. When processing crafted HTML content, the framework may release memory associated with UI elements while still maintaining references to those objects, leading to a use-after-free scenario. This condition allows attackers to manipulate heap memory layout and potentially execute malicious code with the privileges of the browser process. The vulnerability falls under CWE-416, which specifically addresses use-after-free conditions in software development, making it a well-documented and dangerous class of memory safety issues.
The operational impact of CVE-2021-30579 extends beyond simple browser compromise, as successful exploitation can lead to complete system compromise. Attackers can leverage this vulnerability to bypass security restrictions, escalate privileges, and potentially gain persistent access to target systems. The remote exploit nature means that users can be compromised simply by visiting malicious websites or opening crafted email attachments containing HTML content. This vulnerability aligns with ATT&CK technique T1059, where adversaries use command and script interpreters to execute malicious code, and T1071, which involves application layer protocol usage for command and control communications.
Mitigation strategies for this vulnerability primarily focus on immediate remediation through browser updates to version 92.0.4515.107 or later. Organizations should implement comprehensive patch management procedures to ensure all systems receive updates promptly. Additional protective measures include deploying web application firewalls, implementing content security policies, and utilizing sandboxing technologies to limit potential damage from exploitation attempts. Security teams should monitor for indicators of compromise related to this vulnerability and consider implementing browser hardening configurations that restrict memory access patterns. The vulnerability also underscores the importance of regular security assessments and code reviews focused on memory management practices, particularly within UI frameworks where such conditions are most likely to occur.