CVE-2018-6083 in Chrome
Summary
by MITRE
Failure to disallow PWA installation from CSP sandboxed pages in AppManifest in Google Chrome prior to 65.0.3325.146 allowed a remote attacker to access privileged APIs via a crafted HTML page.
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Analysis
by VulDB Data Team • 07/20/2024
The vulnerability identified as CVE-2018-6083 represents a critical security flaw in Google Chrome's implementation of Progressive Web App (PWA) installation mechanisms within the context of Content Security Policy (CSP) sandboxed pages. This issue specifically affected Chrome versions prior to 65.0.3325.146 and allowed remote attackers to bypass intended security restrictions through carefully crafted HTML pages. The flaw stems from Chrome's failure to properly enforce restrictions on PWA installation when pages are loaded within CSP sandboxed environments, creating an unexpected pathway for privilege escalation.
The technical implementation of this vulnerability involves the AppManifest specification and its interaction with Chrome's PWA installation process. When a webpage is loaded within a CSP sandboxed context, the browser should normally restrict access to privileged APIs and installation capabilities that could potentially be exploited. However, Chrome's implementation contained a logic flaw where it permitted PWA installation requests from these sandboxed pages despite the security restrictions that should have prevented such actions. This inconsistency between the expected security boundaries and actual implementation allowed attackers to craft malicious HTML content that could trigger PWA installation while maintaining the sandboxed environment's protective properties.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it creates a potential attack vector for more sophisticated exploitation techniques. An attacker could leverage this flaw to install malicious PWAs that have access to privileged APIs, potentially enabling data exfiltration, persistent access, or further exploitation of the user's browser environment. The vulnerability is particularly concerning because it operates within the legitimate PWA installation framework, making it harder to detect through traditional security monitoring approaches. Attackers could craft seemingly benign web pages that, when visited by users, silently install malicious PWAs with elevated privileges, creating a stealthy persistence mechanism.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-284, which addresses improper access control, and demonstrates characteristics consistent with ATT&CK technique T1059.001 for command and scripting interpreter. The flaw also relates to CWE-352, which covers cross-site request forgery, and represents a form of privilege escalation that could enable attackers to bypass security controls typically enforced by CSP mechanisms. The vulnerability essentially undermines the security model that CSP is designed to enforce, creating an unexpected path for attackers to access privileged browser functionality through legitimate installation pathways.
Mitigation strategies for CVE-2018-6083 primarily involve updating to Chrome version 65.0.3325.146 or later, which contains the necessary patches to properly enforce CSP restrictions during PWA installation processes. Organizations should also implement additional monitoring for suspicious PWA installation activities and consider deploying extended CSP policies that further restrict installation capabilities. Browser vendors and security teams should maintain vigilance regarding similar implementation flaws in web standards, particularly those involving privileged API access and installation mechanisms. The vulnerability underscores the importance of thorough security testing of web platform features and the need for consistent enforcement of security boundaries across all browser functionalities.