CVE-2020-1056 in Edge
Summary
by MITRE
An elevation of privilege vulnerability exists when Microsoft Edge does not properly enforce cross-domain policies, which could allow an attacker to access information from one domain and inject it into another domain.In a web-based attack scenario, an attacker could host a website that is used to attempt to exploit the vulnerability, aka 'Microsoft Edge Elevation of Privilege Vulnerability'.
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Analysis
by VulDB Data Team • 10/16/2020
This vulnerability represents a critical security flaw in Microsoft Edge browser that stems from improper enforcement of cross-domain policies within the browser's security architecture. The issue manifests when the browser fails to adequately separate domains, creating a pathway for malicious actors to exploit the trust boundaries that should normally prevent information leakage between different web domains. This weakness specifically affects the browser's implementation of the same-origin policy, which is a fundamental security mechanism designed to isolate web content from different origins to prevent unauthorized data access and manipulation. The vulnerability has been classified under CWE-284, which addresses improper access control issues, and aligns with ATT&CK technique T1059.003 for command and scripting interpreter usage in exploitation scenarios.
The technical exploitation of this privilege escalation vulnerability occurs through sophisticated cross-site scripting attacks where an attacker crafts malicious web content that can bypass the browser's domain isolation mechanisms. When a user visits a malicious website, the vulnerability allows the attacker to access sensitive information from one domain and potentially inject that data into another domain, effectively breaking the security model that separates different web applications and their associated data. This cross-domain data leakage can enable attackers to access cookies, session tokens, local storage data, or other sensitive information that should remain isolated between different origins. The exploitation process typically involves leveraging the browser's rendering engine to execute malicious scripts that can manipulate the Document Object Model across different domains, creating a persistent threat vector that can be used for further attacks.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to perform sophisticated attacks that can lead to complete account compromise and unauthorized access to user data. Attackers can use this vulnerability to steal user sessions, access personal information, perform unauthorized transactions, or even escalate their privileges within web applications that rely on Edge as their browser. The attack surface is particularly concerning because it affects all users of Microsoft Edge who visit malicious websites, with no user interaction required beyond simply navigating to the compromised site. This makes the vulnerability especially dangerous in phishing campaigns or when exploited through compromised websites that users might legitimately visit, as the attack can occur silently in the background without any visible indication to the user that their security has been compromised.
Organizations and users should implement multiple layers of defense to mitigate this vulnerability, including keeping Microsoft Edge updated with the latest security patches, implementing strict web application firewalls, and monitoring for suspicious cross-domain activity. The recommended mitigations include enabling browser security features such as Content Security Policy headers, disabling unnecessary browser extensions, and implementing user education about avoiding suspicious websites. Security professionals should also consider deploying network monitoring solutions that can detect anomalous cross-domain data transfer patterns and implement regular vulnerability assessments to identify potential exploitation vectors. Additionally, organizations should review their web application security configurations to ensure that they are properly implementing cross-origin resource sharing policies and that their applications are not inadvertently creating additional attack surfaces that could be exploited through this browser vulnerability. The incident response plan should include procedures for detecting and responding to potential exploitation attempts, as well as regular security audits to ensure that all systems remain protected against this and similar cross-domain privilege escalation threats.