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CVE-2021-21220

Google — Google Chromium V8 Improper Input Validation Vulnerability

Google · CWE-787 — Out-of-bounds write · in CISA KEV since 2021-11-03

KEV since 2021 · listed over a yearCISA KEVActively Exploited
78

EVRS 78 of 100 Urgent

Patch This Cycle

Rank 641 of 2,960 tracked

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Why it scores 78

Evidence available: 6 of 7 signals

Listed in the CISA KEV catalog, and an EPSS probability of 0.704.

  • CISA KEVApplied
  • RansomwareDid not apply
  • Vendor exploitationDid not apply
  • EPSSApplied
  • Microsoft Exploitability IndexNot applicable
  • Pre-patch disclosureNo data
  • KEV recencyDid not apply
  • CVSSApplied

The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data

Fix

Patch or fixed version identified

CISA required action

Fixed in

chromium-browser -> 90.0.4430.72-0ubuntu0.16.04.1 | chromium-browser -> 90.0.4430.72-0ubuntu0.18.04.1 | chromium -> 90.0.4430.72-1

Affected versions

  • chrome< 89.0.4389.128
  • fedora323334

Remediation

Apply updates per vendor instructions.

Fixed versions from NVD.

Evidence

Each value with its source
MeasureValueSource
CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. 8.8 NVD
FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. 0.704 (99.39th pctl) FIRST EPSS
Actively exploitedWhether a source of record has confirmed attacks using it in the wild. Confirmed CISA KEV
Ransomware campaign useWhether CISA has seen ransomware operators use it. Unknown or none CISA KEV
CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. 2021-11-17 · KEV since 2021 · listed over a year CISA KEV
Public exploit moduleA module existing is not the same as active exploitation. Public module exists Metasploit
EUVD cross-referenceENISA's record: CVSS 8.8 (v3.1), assigned by Chrome. Listed ENISA EUVD

Description

NVD

Insufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

What CISA says to do

Public module

Metasploit lists a public manual-rank module for this CVE: Google Chrome versions before 89.0.4389.128 V8 XOR Typer Out-Of-Bounds Access RCE (multi/browser/chrome_cve_2021_21220_v8_insufficient_validation). A module existing is not the same as active exploitation; see metasploit.com.