CVE-2020-6392 in Chrome
Summary
by MITRE
Insufficient policy enforcement in extensions in Google Chrome prior to 80.0.3987.87 allowed an attacker who convinced a user to install a malicious extension to bypass navigation restrictions via a crafted Chrome Extension.
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Analysis
by VulDB Data Team • 05/10/2025
The vulnerability identified as CVE-2020-6392 represents a critical weakness in Google Chrome's extension policy enforcement mechanisms that existed prior to version 80.0.3987.87. This flaw specifically targeted the browser's extension management system and created a pathway for attackers to circumvent intended security restrictions through malicious extension installation. The vulnerability falls under the broader category of insufficient policy enforcement, which is categorized as CWE-693 in the Common Weakness Enumeration framework, highlighting the fundamental failure in access control mechanisms that should have prevented unauthorized navigation behavior.
The technical implementation of this vulnerability exploited the gap between Chrome's extension installation process and its subsequent navigation restriction enforcement. Attackers could craft malicious extensions that appeared legitimate to users while containing code designed to bypass the browser's intended navigation controls. This occurred because Chrome's policy enforcement system failed to adequately validate or restrict the navigation capabilities of extensions during or after installation, allowing malicious actors to create extensions that could redirect users to arbitrary web locations without proper authorization checks. The flaw essentially created a loophole where extension permissions could be abused to circumvent security boundaries that should have been enforced by the browser's core security architecture.
The operational impact of this vulnerability was significant as it enabled attackers to perform phishing attacks, redirect users to malicious websites, and potentially harvest sensitive information through social engineering tactics. Users who installed malicious extensions would unknowingly expose themselves to navigation-based attacks that could lead to credential theft, malware distribution, or other malicious activities. The attack vector required user interaction through extension installation, making it particularly dangerous in environments where users might be targeted through spear-phishing campaigns or social engineering. This vulnerability directly impacted the browser's security model by weakening the isolation between user browsing activities and potentially malicious extension behavior, creating a persistent threat vector that could remain active until the user manually removed the extension.
Mitigation strategies for CVE-2020-6392 centered on updating to Chrome version 80.0.3987.87 or later, which implemented enhanced policy enforcement mechanisms for extension navigation restrictions. Organizations should also implement extended security measures including browser hardening, extension management policies, and user education programs to reduce the risk of malicious extension installation. The vulnerability's remediation aligns with ATT&CK framework techniques related to privilege escalation and defense evasion, as attackers could leverage this flaw to bypass security controls and maintain persistent access. Security teams should monitor for suspicious extension installations and implement automated scanning of installed extensions to detect potentially malicious behavior patterns. Additionally, organizations should consider implementing extension whitelisting policies and regular security audits of browser extensions to prevent exploitation of similar vulnerabilities in the future.