CVE-2020-16010: Google Chrome Buffer Overflow Vulnerability

CVE-2020-16010 Overview

CVE-2020-16010 is a critical heap buffer overflow vulnerability affecting the user interface (UI) component of Google Chrome on Android. This memory corruption flaw allows a remote attacker who has already compromised the renderer process to potentially escape the browser sandbox by enticing a victim to visit a maliciously crafted HTML page. The vulnerability represents a significant security risk as sandbox escapes enable attackers to break out of Chrome's security containment and gain broader access to the underlying Android system.

Critical Impact

This vulnerability is actively exploited in the wild and is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog. A successful exploitation chain could allow attackers to bypass Chrome's sandbox protections on Android devices, potentially leading to complete device compromise.

Affected Products

• Google Chrome on Android prior to version 86.0.4240.185
• Google Android (as the underlying platform)
• Mobile browsers based on Chromium rendering engine on Android

Discovery Timeline

• 2020-11-03 - CVE-2020-16010 published to NVD
• 2026-01-14 - Last updated in NVD database

Technical Details for CVE-2020-16010

Vulnerability Analysis

This vulnerability is classified as a heap buffer overflow (CWE-787: Out-of-bounds Write, CWE-122: Heap-based Buffer Overflow) residing in the UI component of Google Chrome for Android. The flaw occurs when Chrome improperly handles certain memory operations while processing UI elements, allowing an attacker to write data beyond the allocated heap buffer boundaries.

What makes this vulnerability particularly dangerous is its role as a sandbox escape primitive. Chrome employs a multi-process architecture where the renderer process (which executes untrusted web content) runs in a sandboxed environment with restricted privileges. This vulnerability allows an attacker who has already achieved code execution within the renderer process to break out of that sandbox and gain elevated privileges on the Android device.

The exploitation requires user interaction—specifically, the victim must navigate to or be redirected to a malicious webpage. Once triggered, the heap overflow can corrupt adjacent memory structures, potentially allowing the attacker to hijack control flow and execute arbitrary code outside the sandbox boundaries.

Root Cause

The root cause of CVE-2020-16010 lies in improper bounds checking within Chrome's UI handling code on Android. When processing certain UI elements or operations, the affected code fails to properly validate buffer sizes before writing data to heap-allocated memory. This oversight creates a condition where specially crafted input can cause the application to write data beyond the intended buffer boundaries, corrupting adjacent heap memory.

The vulnerability specifically affects the Android variant of Chrome, suggesting the issue resides in platform-specific UI code that handles touchscreen interactions, gesture processing, or other mobile-specific interface elements that differ from the desktop implementation.

Attack Vector

The attack vector for CVE-2020-16010 is network-based and requires user interaction. An attacker would typically employ the following exploitation approach:

1. Initial Compromise: The attacker first needs to achieve code execution within Chrome's renderer process, typically through a separate vulnerability
2. Crafted Payload Delivery: The attacker hosts or injects a malicious HTML page designed to trigger the heap buffer overflow
3. User Interaction: The victim must visit the malicious page or be redirected to it through phishing, malvertising, or compromised legitimate websites
4. Sandbox Escape: Upon page load, the crafted content triggers the heap overflow in the UI component, allowing the attacker to escape the renderer sandbox
5. Privilege Escalation: With sandbox escape achieved, the attacker gains broader access to the Android system beyond Chrome's security constraints

The vulnerability is documented in Chromium Issue Tracker Entry. Technical exploitation details should be referenced from the official Google Chrome Android Update security advisory.

Detection Methods for CVE-2020-16010

Indicators of Compromise

• Unexpected Chrome crashes on Android devices followed by suspicious system behavior
• Network connections to known malicious domains serving exploit payloads
• Unusual process spawning or privilege escalation attempts originating from Chrome processes
• Memory access violations or heap corruption signatures in Android crash logs

Detection Strategies

• Monitor Android system logs for Chrome process anomalies, including unexpected crashes with heap corruption indicators
• Implement network-based detection for known malicious payloads targeting Chrome UI vulnerabilities
• Deploy endpoint detection and response (EDR) solutions capable of identifying sandbox escape attempts
• Utilize mobile threat detection (MTD) solutions to identify suspicious application behavior on Android devices

Monitoring Recommendations

• Enable verbose logging on managed Android devices to capture Chrome process behavior
• Monitor for indicators of renderer compromise that may precede sandbox escape attempts
• Implement network traffic analysis to detect connections to suspicious domains
• Review Chrome version deployments across managed device fleets to ensure vulnerable versions are identified

How to Mitigate CVE-2020-16010

Immediate Actions Required

• Update Google Chrome on all Android devices to version 86.0.4240.185 or later immediately
• Enable automatic updates for Chrome on all managed Android devices
• Consider temporary restrictions on web browsing from unpatched devices in high-security environments
• Review enterprise mobile device management (MDM) policies to enforce browser version requirements

Patch Information

Google has addressed this vulnerability in Chrome for Android version 86.0.4240.185. The fix was released in November 2020 as documented in the Google Chrome Android Update. Organizations should ensure all Android devices running Chrome are updated to this version or later.

Given this vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog and has been actively exploited in the wild, patching should be treated as an urgent priority. Federal agencies and organizations following CISA guidance should adhere to the required remediation timelines specified in the CISA Known Exploited Vulnerability entry.

Workarounds

• Use alternative browsers on Android devices until Chrome can be updated (noting this may introduce other security considerations)
• Implement network-level URL filtering to block access to known malicious sites
• Restrict browsing to trusted sites only through enterprise proxy configurations
• Consider disabling JavaScript on high-value devices if operational requirements permit

# Verify Chrome version on Android devices via ADB
adb shell dumpsys package com.android.chrome | grep versionName
# Expected output should show version 86.0.4240.185 or higher

# Force Chrome update check (requires device connectivity)
adb shell am start -a android.intent.action.VIEW -d "market://details?id=com.android.chrome"