Google Chrome V8 Use-After-Free Vulnerability (CVE-2021-37975) Technical Analysis and Mitigation Guide
Executive & SecOps Summary
SECOPS ASSESSMENTGoogle Chrome prior to version 94.0.4606.71
A remote attacker can exploit a heap corruption vulnerability via a crafted HTML page, potentially leading to arbitrary remote code execution (RCE) within the browser renderer process.
Immediately update Google Chrome to the latest stable version (94.0.4606.71 or higher).
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
To upgrade Google Chrome to the patched version on Linux (Ubuntu/Debian-based systems), execute the following commands:
# Update package lists and upgrade Google Chrome to the latest stable version
sudo apt-get update && sudo apt-get --only-upgrade install google-chrome-stable -y2. Temporary Workaround & Hardening Configuration
If immediate patching is not feasible, enforce security policies via registry settings or Group Policy Objects (GPO) to ensure browser sandboxing is strictly enabled.
# Force enable Chrome sandbox policies via Windows Registry
New-Item -Path 'HKLM:\SOFTWARE\Policies\Google\Chrome' -Force | Out-Null
New-ItemProperty -Path 'HKLM:\SOFTWARE\Policies\Google\Chrome' -Name 'SandboxHTML5APIs' -Value 1 -PropertyType DWord -Force3. Log Audit & IoC Verification Commands
Use the following script to audit the currently installed Google Chrome version and verify if it is vulnerable to CVE-2021-37975.
# Check installed Chrome version and compare with the patched version
CHROME_VERSION=$(google-chrome --version | awk '{print $3}')
REQUIRED_VERSION='94.0.4606.71'
if [ '$(printf '%s\
' '$REQUIRED_VERSION' '$CHROME_VERSION' | sort -V | head -n1)' = '$REQUIRED_VERSION' ]; then
echo '[SAFE] Chrome version is $CHROME_VERSION (Equal or higher than $REQUIRED_VERSION)'
else
echo '[WARNING] Chrome version is $CHROME_VERSION. Vulnerable to CVE-2021-37975! Please update immediately.'
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Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability (CVE-2021-37975) is a Use-After-Free (UAF) flaw within the V8 JavaScript and WebAssembly engine of Google Chrome. It stems from improper memory management and object lifecycle handling inside V8. When certain JavaScript objects are garbage collected or manipulated via specific APIs, the engine fails to clear dangling pointers, leaving references to already freed memory locations.
2. Exploitation Mechanics & Attack Scenario
An attacker can exploit this vulnerability by hosting a specially crafted HTML page containing malicious JavaScript. When a target user visits the malicious website, the V8 engine processes the script, triggering the Use-After-Free condition. By leveraging heap layout manipulation techniques (such as heap spraying), the attacker can overwrite the freed memory space with controlled payloads, hijack the execution flow, and execute arbitrary code in the context of the browser's renderer process.
3. Infrastructure & Business Impact
As a vulnerability listed in the CISA KEV catalog, this flaw has been actively exploited in the wild. Successful exploitation allows attackers to compromise the user's endpoint. If combined with a secondary sandbox escape vulnerability, it can lead to full system compromise, enabling lateral movement and unauthorized access to sensitive corporate networks and data.
Official Vendor Advisories & References
Use after free in V8 in Google Chrome prior to 94.0.4606.71 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Frequently Asked SecOps Questions (CVE-2021-37975)
FAQQ1. How critical is CVE-2021-37975 and is it actively exploited in the wild?
CVE-2021-37975 is rated CVSS 8.8 (HIGH) with a 30-day EPSS exploitation probability of 34.9%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2021-37975?
Primary impacted vendors include google across chrome. Scope summary: Google Chrome prior to version 94.0.4606.71 (All desktop platforms including Windows, macOS, and Linux)
Q3. What temporary mitigations or workarounds exist for CVE-2021-37975 before patching?
[Mitigation] Immediately update Google Chrome to the latest stable version (94.0.4606.71 or higher). Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.
Generate an Internal Engineering Notice or CISO Report for CVE-2021-37975
Instantly format this advisory into an executive CISO summary or engineering patch ticket.
🔗 Related Advisories in Similar Stack (google)
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