CVE-2018-8470 in Internet Explorer
Summary
by MITRE
A security feature bypass vulnerability exists in Internet Explorer due to how scripts are handled that allows a universal cross-site scripting (UXSS) condition, aka "Internet Explorer Security Feature Bypass Vulnerability." This affects Internet Explorer 11.
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Analysis
by VulDB Data Team • 05/08/2023
The CVE-2018-8470 vulnerability represents a critical security feature bypass in Microsoft Internet Explorer 11 that enables universal cross-site scripting conditions. This vulnerability stems from improper handling of scripts within the browser's security model, specifically affecting how Internet Explorer processes and validates script execution contexts. The flaw allows attackers to circumvent fundamental security mechanisms that should prevent malicious scripts from executing in restricted environments. The vulnerability is particularly dangerous because it affects the core security features that protect users from cross-site scripting attacks, which are among the most prevalent and dangerous web application vulnerabilities in the cybersecurity landscape. The issue manifests when Internet Explorer fails to properly validate script contexts, creating opportunities for attackers to execute malicious code across different security boundaries.
The technical implementation of this vulnerability involves a flaw in Internet Explorer's script handling mechanism where the browser incorrectly processes certain script execution scenarios that should be blocked by security features. This occurs at the browser engine level where script validation logic fails to properly distinguish between trusted and untrusted script contexts, allowing malicious scripts to bypass security restrictions that normally prevent cross-site scripting attacks. The vulnerability specifically impacts Internet Explorer 11's security model, which relies on various security features including script isolation, context validation, and privilege controls. When exploited, the flaw enables attackers to execute arbitrary code in the context of the victim's session, effectively undermining the browser's security architecture and allowing for complete compromise of the user's browsing environment. This represents a fundamental breakdown in the browser's security model that should have prevented such cross-site scripting conditions.
The operational impact of CVE-2018-8470 is severe and far-reaching, as it provides attackers with a pathway to bypass multiple security controls that protect users from malicious web content. The vulnerability enables attackers to perform universal cross-site scripting attacks that can steal session cookies, credentials, and other sensitive information from users browsing through Internet Explorer 11. Security researchers have classified this vulnerability as particularly dangerous because it allows attackers to exploit the browser's security features rather than simply bypassing them, making detection and mitigation more challenging. The vulnerability can be exploited through various attack vectors including malicious websites, email attachments, and compromised web services that users trust. Organizations that still maintain Internet Explorer 11 in their environments face significant risk of data breaches and system compromise, as the vulnerability can be leveraged to gain persistent access to user systems and potentially escalate privileges to administrative levels.
Mitigation strategies for CVE-2018-8470 require immediate action to address the underlying security feature bypass issue in Internet Explorer 11. Microsoft has released patches and updates to address this vulnerability, but organizations must ensure that all systems are properly updated and that legacy Internet Explorer installations are migrated to supported browsers. The recommended approach includes implementing browser hardening techniques such as disabling unnecessary features, configuring security zones properly, and deploying additional security controls like application whitelisting and network monitoring. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts. Security teams must understand that this vulnerability aligns with ATT&CK technique T1211 which involves exploitation of security features, and CWE-20 which represents improper input validation. The vulnerability demonstrates the critical importance of maintaining up-to-date browser security implementations and highlights the risks associated with legacy browser support in enterprise environments. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other browser components and web applications that may be susceptible to similar exploitation techniques.