CVE-2019-13705 in Chrome
Summary
by MITRE
Insufficient policy enforcement in extensions in Google Chrome prior to 78.0.3904.70 allowed an attacker who convinced a user to install a malicious extension to leak cross-origin data via a crafted Chrome Extension.
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Analysis
by VulDB Data Team • 02/27/2024
This vulnerability represents a critical weakness in Google Chrome's extension security model that existed prior to version 78.0.3904.70. The flaw stems from inadequate policy enforcement mechanisms that govern how browser extensions interact with cross-origin resources. Under normal circumstances, web browsers implement strict security boundaries to prevent malicious extensions from accessing data from different origins, but this vulnerability created a pathway for bypassing those protections. The issue specifically affects Chrome's extension architecture where the browser fails to properly validate or restrict the scope of permissions granted to installed extensions, particularly when those extensions attempt to access resources across different origins.
The technical implementation of this vulnerability allows a malicious actor to craft a specially designed Chrome extension that can exploit the insufficient policy enforcement to exfiltrate cross-origin data. This occurs because the extension system does not adequately verify or constrain the capabilities of extensions when they attempt to access resources from domains other than their own. Attackers can leverage this weakness by convincing users to install a seemingly legitimate extension that contains hidden malicious code. The extension can then perform unauthorized data access operations across different origins, potentially harvesting sensitive information from multiple websites or applications. This represents a fundamental breakdown in Chrome's security model where the principle of least privilege is not properly enforced for extension permissions.
The operational impact of this vulnerability extends beyond simple data theft to encompass broader security implications for users and organizations. When an attacker successfully installs a malicious extension, they gain the ability to monitor and collect cross-origin data without the user's knowledge or consent. This could include accessing personal information from social media accounts, financial data from banking applications, or confidential business information from enterprise systems. The vulnerability is particularly dangerous because it operates at the browser level where extensions have elevated privileges and can bypass traditional web application security controls. Organizations may experience significant data breaches or privacy violations when employees install compromised extensions, and the attack vector is often difficult to detect since the malicious behavior occurs within the trusted browser environment.
Mitigation strategies for this vulnerability require a multi-layered approach that addresses both immediate remediation and long-term security posture improvements. The primary solution involves updating to Chrome version 78.0.3904.70 or later where the policy enforcement mechanisms have been strengthened to properly restrict cross-origin access by extensions. Organizations should also implement strict extension installation policies that limit which extensions can be installed on corporate devices and regularly audit installed extensions for suspicious behavior. Browser security configurations should be hardened by disabling unnecessary extension permissions and implementing additional monitoring for extension activities. Security teams should conduct regular vulnerability assessments to identify potentially compromised extensions and establish procedures for rapid response to extension-related security incidents. This vulnerability aligns with CWE-284, which addresses insufficient access control, and represents a specific instance of how inadequate privilege management in browser extensions can create security risks that align with ATT&CK techniques focused on privilege escalation and credential access.
The broader implications of this vulnerability highlight the challenges inherent in browser extension security models where the trust relationship between users and extensions is often exploited. Chrome's extension ecosystem must balance user convenience with security requirements, but this particular flaw demonstrates that insufficient policy enforcement creates dangerous attack surfaces. The vulnerability underscores the importance of proper sandboxing and access control mechanisms in browser environments, as well as the need for continuous security review of extension permissions and capabilities. Organizations relying on Chrome-based environments should consider implementing additional security controls such as extension whitelisting, network monitoring for suspicious data exfiltration patterns, and user education programs about the risks of installing untrusted extensions. The remediation process should include comprehensive testing to ensure that legitimate extensions continue to function properly while malicious extensions are properly blocked or detected.