CVE-2020-6495 in Chrome
Summary
by MITRE
Insufficient policy enforcement in developer tools in Google Chrome prior to 83.0.4103.97 allowed an attacker who convinced a user to install a malicious extension to potentially perform a sandbox escape via a crafted Chrome Extension.
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Analysis
by VulDB Data Team • 05/05/2025
The vulnerability identified as CVE-2020-6495 represents a critical security flaw in Google Chrome's extension management system that existed prior to version 83.0.4103.97. This weakness stems from inadequate policy enforcement mechanisms within the browser's developer tools framework, creating a pathway for malicious actors to exploit the extension installation process. The vulnerability specifically targets the sandbox isolation model that Chrome employs to protect users from potentially harmful extensions, fundamentally undermining the security boundaries that separate trusted browser components from untrusted extension code.
The technical flaw manifests through a sandbox escape vector that leverages the trust model inherent in Chrome's extension architecture. When a user installs a malicious extension, the vulnerability allows an attacker to bypass the normal security checks that should prevent arbitrary code execution outside the designated extension sandbox. This occurs because the developer tools implementation fails to properly validate the extension's permissions and capabilities during installation, enabling a crafted extension to manipulate the browser's security boundaries. The flaw operates at the intersection of browser extension management and sandboxing mechanisms, creating a direct pathway for privilege escalation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to potentially access sensitive user data, perform unauthorized network communications, and manipulate browser functionality. A successful exploitation could allow an attacker to execute arbitrary code with the privileges of the Chrome browser process, potentially leading to full system compromise. The attack vector requires social engineering to convince users to install the malicious extension, but once installed, the vulnerability provides a persistent backdoor that operates at the browser level, making detection and remediation particularly challenging.
This vulnerability aligns with CWE-284, which addresses insufficient access control, and demonstrates how inadequate policy enforcement can create security boundaries that are easily circumvented. The issue also maps to several ATT&CK techniques including T1176 for Browser Extensions and T1059 for Command and Scripting Interpreter, as the malicious extension could be used to execute commands or scripts within the browser environment. Organizations should prioritize immediate patching to version 83.0.4103.97 or later, while implementing monitoring for suspicious extension installations. Additional mitigations include restricting extension installation permissions, conducting regular security audits of installed extensions, and educating users about the risks of installing extensions from untrusted sources. Network-level monitoring should also be implemented to detect unusual browser behavior that might indicate exploitation attempts.