CVE-2020-6442 in Chrome
Summary
by MITRE
Inappropriate implementation in cache in Google Chrome prior to 81.0.4044.92 allowed a remote attacker to leak cross-origin data via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/09/2025
The vulnerability identified as CVE-2020-6442 represents a critical security flaw in Google Chrome's caching mechanism that existed prior to version 81.0.4044.92. This issue stems from an inappropriate implementation in how Chrome handles cached data, specifically when processing cross-origin resources. The flaw enables remote attackers to exploit the browser's caching behavior to access sensitive data from different origins, creating a significant bypass of web security boundaries that should normally prevent such information leakage.
The technical implementation flaw manifests in Chrome's cache management system where the browser fails to properly enforce cross-origin isolation policies when serving cached content. When a malicious actor crafts a specific HTML page that triggers particular caching behaviors, the browser's cache can inadvertently serve data from one origin to another, effectively leaking cross-origin information. This vulnerability operates at the intersection of web security principles and browser cache management, where the expected isolation between different origins breaks down due to improper cache handling. The issue is particularly dangerous because it leverages legitimate browser functionality to create an unexpected data exposure channel.
The operational impact of CVE-2020-6442 extends beyond simple information leakage, as it can potentially enable sophisticated attacks such as cross-site scripting exploitation, session hijacking, or sensitive data exfiltration. Attackers can craft malicious web pages that, when loaded in a victim's browser, trigger the cache behavior to access resources from other domains that the victim should not be able to access. This could include accessing cookies, authentication tokens, or other sensitive data that should remain isolated between different origins. The vulnerability affects all Chrome versions prior to 81.0.4044.92 and represents a significant weakening of the browser's security model, particularly in how it handles cached resources across different security domains.
This vulnerability aligns with CWE-200, which describes "Information Exposure" and specifically addresses improper information exposure through cache mechanisms. The flaw also relates to ATT&CK technique T1071.001, "Application Layer Protocol: Web Protocols," as it exploits web browser protocols and caching behaviors. Additionally, it connects to T1566, "Phishing," since attackers can leverage this vulnerability to craft convincing phishing pages that can access cross-origin data. The remediation involves updating Chrome to version 81.0.4044.92 or later, where Google implemented proper cache isolation mechanisms. Organizations should also consider implementing network-level protections, browser hardening measures, and monitoring for suspicious caching behavior. The fix addresses the root cause by ensuring that cached content properly enforces cross-origin policies and prevents unauthorized data sharing between different security domains.