Google Chrome Indexed DB API Use-After-Free Vulnerability (CVE-2021-30633) Analysis and Mitigation Guide
Executive & SecOps Summary
SECOPS ASSESSMENTGoogle Chrome prior to version 93.0.4577.82
A remote attacker who has compromised the renderer process can potentially execute arbitrary code and escape the browser sandbox via a crafted HTML page
Immediately update Google Chrome to the latest stable version (93.0.4577.82 or higher)
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
To upgrade Google Chrome to the latest secure 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 -y
# Verify the installed version
google-chrome --version2. Temporary Workaround & Hardening Configuration
In enterprise environments where immediate patching is not feasible, enforce Chrome automatic updates via Group Policy (GPO) or registry settings to minimize the window of exposure.
# Force Google Chrome automatic updates via Windows PowerShell
New-Item -Path 'HKLM:\SOFTWARE\Policies\Google\Update' -Force
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Policies\Google\Update' -Name 'UpdateDefault' -Value 13. Log Audit & IoC Verification Commands
Use the following Bash script to audit local systems and identify vulnerable installations of Google Chrome.
#!/bin/bash
# Audit script for Google Chrome vulnerability status
if command -v google-chrome &> /dev/null; then
CURRENT_VER=$(google-chrome --version | awk '{print $3}')
REQUIRED_VER='93.0.4577.82'
if [ '$(printf '%s\
' "$REQUIRED_VER" "$CURRENT_VER" | sort -V | head -n1)' != "$REQUIRED_VER" ]; then
echo '[WARNING] Chrome version '$CURRENT_VER' is vulnerable. Please upgrade immediately.'
else
echo '[OK] Chrome version '$CURRENT_VER' is secure.'
fi
else
echo '[INFO] Google Chrome is not installed.'
fiBlock Kernel Privilege Escalation & Ransomware Payloads Before You Can Reboot
Protect unpatched Windows, Linux, and macOS workloads against in-memory exploitation and lateral movement with autonomous EDR.
Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability (CVE-2021-30633) is a Use-After-Free (UAF) flaw residing within the Indexed DB API implementation of Google Chrome. Indexed DB is a transactional database system used for storing large amounts of structured data inside the browser. Due to improper lifecycle management of database objects and transactions, the browser attempts to reference an object pointer that has already been freed from memory, leading to memory corruption.
2. Exploitation Mechanics & Attack Scenario
To exploit this vulnerability, an attacker must first compromise the Chrome renderer process, typically by chaining another vulnerability. Once inside the renderer, the attacker lures the victim to a malicious HTML page containing crafted JavaScript. This script triggers the creation and premature destruction of Indexed DB objects, reclaiming the freed memory space with attacker-controlled data. When the renderer process subsequently dereferences the stale pointer, control flow is hijacked, allowing the attacker to bypass the Chrome sandbox and execute code on the host OS.
3. Infrastructure & Business Impact
This vulnerability has been actively exploited in the wild and is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Successful exploitation allows an attacker to escape the browser sandbox and gain full execution privileges on the user's local machine. This can lead to unauthorized access to sensitive corporate data, lateral movement within the internal network, and deployment of ransomware.
Official Vendor Advisories & References
Use after free in Indexed DB API in Google Chrome prior to 93.0.4577.82 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.
Frequently Asked SecOps Questions (CVE-2021-30633)
FAQQ1. How critical is CVE-2021-30633 and is it actively exploited in the wild?
CVE-2021-30633 is rated CVSS 9.6 (CRITICAL) with a 30-day EPSS exploitation probability of 33.2%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2021-30633?
Primary impacted vendors include google across chrome. Scope summary: All Google Chrome desktop versions prior to 93.0.4577.82 (Windows, macOS, Linux)
Q3. What temporary mitigations or workarounds exist for CVE-2021-30633 before patching?
[Mitigation] Immediately update Google Chrome to the latest stable version (93.0.4577.82 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-2021-30633
Instantly format this advisory into an executive CISO summary or engineering patch ticket.
🔗 Related Advisories in Similar Stack (google)
View Category →Google Chrome Dawn Use-After-Free Vulnerability (CVE-2026-5281) Technical Advisory
[Affected Scope] Google Chrome versions prior to 146.0.7680.178
Google Chrome V8 Out-of-bounds Write Remote Code Execution Advisory (CVE-2026-87491)
[Affected Scope] Google Chrome versions prior to 153.0.8010.36 and Chromium-based browsers
Google Chrome V8 Type Confusion Vulnerability (CVE-2026-85046) - Remote Code Execution in Sandbox
[Affected Scope] Google Chrome and Chromium-based browsers prior to version 152.0.7977.82
Google Chrome V8 Out-of-Bounds Read/Write Vulnerability (CVE-2026-11645) Advisory
[Affected Scope] Google Chrome and Chromium-based browsers prior to version 149.0.7827.103
Subscribe to Daily Vulnerability Briefings & KEV Alerts
Concise morning briefings for SecOps, DevSecOps, and SRE teams covering newly exploited CVEs and mitigation priorities.