CVE-2020-6395 in Chrome
Summary
by MITRE
Out of bounds read in JavaScript in Google Chrome prior to 80.0.3987.87 allowed a remote attacker to obtain potentially sensitive information from process memory via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/10/2025
The vulnerability identified as CVE-2020-6395 represents a critical out-of-bounds read flaw within the JavaScript engine of Google Chrome browser versions prior to 80.0.3987.87. This issue falls under the Common Weakness Enumeration category CWE-129, which specifically addresses improper validation of array indices or similar bounds checks. The vulnerability occurs when the browser processes crafted HTML content that triggers an invalid memory access pattern within the JavaScript execution environment.
The technical implementation of this flaw involves the JavaScript engine's failure to properly validate memory access boundaries when processing certain array operations or object property accesses. When a maliciously crafted HTML page is loaded, it can cause the browser to read memory locations beyond the intended array or buffer boundaries. This memory access pattern allows an attacker to potentially extract sensitive data from adjacent memory regions, including potentially confidential information such as cryptographic keys, user credentials, or other process-specific data that may be stored in memory.
From an operational perspective, this vulnerability creates a significant risk for remote code execution and information disclosure attacks. Attackers can leverage this flaw by hosting malicious web content that, when viewed in an affected browser version, triggers the out-of-bounds read condition. The attack vector is particularly dangerous because it requires no user interaction beyond visiting a compromised website, making it a prime candidate for drive-by download attacks. The potential impact extends beyond simple information disclosure, as the leaked memory contents could contain enough sensitive data to facilitate more sophisticated attacks such as privilege escalation or credential theft.
The security implications of this vulnerability align with ATT&CK technique T1059.007 for JavaScript-based attacks and T1068 for privilege escalation through memory corruption. Organizations running affected Chrome versions face immediate risk of data breaches and system compromise. The vulnerability demonstrates how seemingly minor flaws in memory management can create substantial security risks in modern web browsers that process complex JavaScript code. Browser vendors typically address such issues through memory safety improvements, bounds checking enhancements, and regular security updates that prevent invalid memory operations from occurring in the first place.
Mitigation strategies for this vulnerability include immediate deployment of Chrome version 80.0.3987.87 or later, which contains the necessary fixes to prevent the out-of-bounds read condition. Security administrators should also implement additional protective measures such as browser hardening configurations, content security policies, and regular vulnerability assessments to identify and remediate similar issues. The fix typically involves implementing proper bounds checking in the JavaScript engine's memory management routines and ensuring that all array access operations validate their indices against the actual array size before accessing memory locations.