Is CVE-2021-21220 actively exploited?

Yes. CVE-2021-21220 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-21220 be exploited remotely?

The attack vector of CVE-2021-21220 has not been classified yet.

What is the CVSS score of CVE-2021-21220?

CVE-2021-21220 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-21220

HIGHCISA KEVIN THE WILD

CVE-2021-21220

Published: November 3, 2021

EPSS:92.59%probability of exploitation in 30 daysPercentile:99.7th

Official Description

Google Chromium V8 Engine contains an improper input validation vulnerability that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.

NVD Source

CISA KEV Advisory

Google Chromium V8 Improper Input Validation Vulnerability

Added to KEV: 2021-11-03Federal patch deadline: 2021-11-17

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

This vulnerability in the Google Chromium V8 Engine allows a remote attacker to potentially exploit heap corruption via a crafted HTML page due to improper input validation. This flaw affects multiple web browsers utilizing Chromium, including Google Chrome, Microsoft Edge, and Opera. Its high EPSS score of 0.92595 and inclusion in CISA's KEV indicate a high likelihood of exploitation.

This vulnerability is actively exploited in the wild and is listed in CISA's KEV, confirming its active use by threat actors. The remote nature of exploitation through crafted HTML pages makes it a significant threat to browser users.

Recommended Action

Users should ensure their web browsers (e.g., Google Chrome, Microsoft Edge, Opera) are updated to the latest versions to patch the Chromium V8 Engine. Exercise caution when visiting untrusted websites.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-21220 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-21220 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.