CVE-2018-6148 in Chrome
Summary
by MITRE
Incorrect implementation in Content Security Policy in Google Chrome prior to 67.0.3396.79 allowed a remote attacker to bypass navigation restrictions via a crafted HTML page.
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Analysis
by VulDB Data Team • 07/18/2024
The vulnerability identified as CVE-2018-6148 represents a critical flaw in Google Chrome's implementation of Content Security Policy (CSP) mechanisms that governed navigation restrictions within web browsers. This weakness existed in Chrome versions prior to 67.0.3396.79 and enabled malicious actors to circumvent intended security controls that were designed to prevent unauthorized navigation to specific domains or resources. The vulnerability specifically targeted the browser's enforcement of CSP directives that were meant to restrict where users could be navigated programmatically or through user interaction.
The technical implementation flaw stemmed from how Chrome processed and enforced CSP policies when handling navigation events within web pages. Attackers could craft malicious HTML pages that exploited a gap in the browser's CSP enforcement logic, allowing them to bypass restrictions that should have prevented navigation to external domains or specific URLs. This occurred when the browser failed to properly validate navigation requests against CSP policies, particularly those related to the 'navigate-to' directive or similar navigation restriction mechanisms. The flaw essentially allowed attackers to perform unauthorized redirects or navigations that would normally be blocked by CSP policies.
The operational impact of this vulnerability was significant as it enabled remote code execution and information disclosure attacks through social engineering techniques. An attacker could create a malicious webpage that appeared legitimate to users while simultaneously bypassing security controls that would normally prevent navigation to phishing sites or malicious domains. This created a dangerous scenario where users could be redirected to attacker-controlled resources without their knowledge or consent, potentially leading to credential theft, malware delivery, or other malicious activities. The vulnerability was particularly concerning because it undermined the fundamental security model that CSP was designed to enforce.
This vulnerability aligns with CWE-693, which covers protection mechanism failures, specifically relating to inadequate enforcement of access control mechanisms. The issue also maps to ATT&CK technique T1059, which involves executing malicious code through web-based attacks, and T1190, which covers exploiting vulnerabilities in web applications. The flaw demonstrated how improper implementation of security controls could create attack vectors that bypassed multiple layers of web security. Organizations relying on CSP as a defense-in-depth mechanism found their protection compromised, as attackers could leverage this vulnerability to circumvent browser-based security policies. The vulnerability highlighted the importance of thorough testing and validation of security controls, particularly those related to navigation and redirection enforcement in web browsers.
Mitigation strategies for CVE-2018-6148 required immediate updates to Chrome browsers to version 67.0.3396.79 or later, which contained the patched implementation of CSP navigation restrictions. Organizations should have implemented additional monitoring for suspicious navigation patterns and ensured that CSP policies were properly configured and enforced across their web applications. Security teams needed to conduct vulnerability assessments to identify potential exploitation attempts and verify that their CSP configurations were not susceptible to similar implementation flaws. The incident underscored the necessity of maintaining up-to-date browser versions and the importance of comprehensive security testing for browser-based security controls.