CVE-2018-0803 in Edge
Summary
by MITRE
Microsoft Edge in Microsoft Windows 10 Gold, 1511, 1607, 1703, 1709, and Windows Server 2016 allows an attacker to access information from one domain and inject it into another domain, due to how Microsoft Edge enforces cross-domain policies, aka "Microsoft Edge Elevation of Privilege Vulnerability".
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Analysis
by VulDB Data Team • 01/28/2021
This vulnerability exists in Microsoft Edge browser across multiple Windows 10 versions and Windows Server 2016, representing a critical cross-domain policy enforcement flaw that enables unauthorized information disclosure and injection attacks. The issue stems from how Edge handles cross-origin resource sharing and domain isolation mechanisms, creating a pathway for malicious actors to bypass security boundaries between different web domains. This weakness allows an attacker to access data from one domain and inject malicious content into another domain, fundamentally undermining the browser's security model.
The technical flaw manifests through improper enforcement of same-origin policy restrictions within the Edge rendering engine, specifically in how it manages cross-domain communication channels. When a malicious website attempts to access resources or data from a different domain, the browser fails to properly validate the cross-domain access requests, creating a potential information leakage vector. This vulnerability is categorized under CWE-284 which addresses improper access control mechanisms, and it directly relates to the broader class of cross-site scripting and cross-domain policy violations that have plagued web browsers for decades.
The operational impact of this vulnerability is severe as it enables attackers to perform elevation of privilege operations by exploiting the browser's domain isolation mechanisms. An attacker could potentially steal session cookies, access sensitive user data, or inject malicious scripts into trusted domains, leading to complete compromise of user sessions and potential lateral movement within corporate networks. This vulnerability particularly affects enterprise environments where users may browse both internal and external domains, creating opportunities for attackers to bridge security boundaries between different network segments. The attack surface is significant given that Edge is the default browser on Windows 10 systems and is widely used in enterprise environments.
Mitigation strategies should include immediate deployment of Microsoft security patches and updates, which address the core cross-domain policy enforcement issues. Organizations should also implement additional network-level protections such as content filtering solutions and web application firewalls to monitor and block suspicious cross-domain communication patterns. Browser hardening measures including disabling unnecessary cross-domain access capabilities, implementing strict content security policies, and configuring enhanced tracking protection features can help reduce the risk exposure. Security teams should also conduct regular vulnerability assessments focusing on browser security configurations and monitor for anomalous cross-domain data access patterns that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques and credential access methods, emphasizing the need for comprehensive defensive measures across multiple security layers to prevent successful exploitation.