Threats / Google / CVE-2021-21224
CVE-2021-21224
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Google Chromium V8 vulnerability
Type confusion vulnerability in Chromium V8 allows remote code execution within sandbox via crafted HTML, affecting Chrome, Edge, and Opera browsers.
Verdict
Today item — known-exploited.
A type confusion flaw in V8 enables attackers to execute arbitrary code within the browser sandbox by delivering malicious HTML. Active exploitation in the wild demonstrates practical threat; sandbox escape potential elevates risk to system compromise.
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
2 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
Probability (EPSS)
EPSS 0.57736 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Google, Chromium V8. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-843 Type Confusion — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious HTML page that triggers type confusion in the V8 JavaScript engine.
Business
Users visiting attacker-controlled or compromised websites face code execution within browser sandbox.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I exploit the type confusion to execute arbitrary JavaScript code with elevated privileges within the sandbox.
Business
Sensitive user data, credentials, and session tokens become accessible to the attacker through compromised browser context.
3
Lateral reach — past segmentation narrative 3
Attacker
I attempt to chain this vulnerability with sandbox escape techniques to gain system-level access.
Business
Potential for full device compromise, malware installation, and lateral movement across enterprise networks.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05