CVE-2021-21220
Confirmed PUBLISHEDInsufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap...
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Apr 26, 2021
- Exploitation Reported
- Nov 03, 2021
- CVSS
- 8.8 High
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
|
Chrome
|
unspecified to < 89.0.4389.128 |
Affected |
CVE References
- GLSA-202104-08 security.gentoo.org · Vendor Advisory https://security.gentoo.org/glsa/202104-08
- FEDORA-2021-c3754414e7 lists.fedoraproject.org · Vendor Advisory https://lists.fedoraproject.org/archives/list/package-announce%40list...
- FEDORA-2021-ff893e12c5 lists.fedoraproject.org · Vendor Advisory https://lists.fedoraproject.org/archives/list/package-announce%40list...
- FEDORA-2021-35d2bb4627 lists.fedoraproject.org · Vendor Advisory https://lists.fedoraproject.org/archives/list/package-announce%40list...
- chromereleases.googleblog.com/2021/04/stable-channel-update-for-desktop.html chromereleases.googleblog.com · CVE Record https://chromereleases.googleblog.com/2021/04/stable-channel-update-f...
Show 3 more references
- crbug.com/1196683 crbug.com · CVE Record https://crbug.com/1196683
- packetstormsecurity.com/files/162437/Google-Chrome-XOR-Typer-Out-Of-... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/162437/Google-Chrome-XOR-Typer-O...
- packetstormsecurity.com/files/176210/Chrome-V8-JIT-XOR-Arbitrary-Cod... packetstormsecurity.com · CVE Record http://packetstormsecurity.com/files/176210/Chrome-V8-JIT-XOR-Arbitra...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2021-11-03 00:00 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/browser/chrome_cve_2021_21220_v8_insufficient_validation.rb | Apr 28, 2025 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AV:N/AC:M/Au:N/C:P/I:P/A:P
Exploitation Status
Exploited in the wild
Recorded 2021-11-03 00:00:00 UTC · CISA
Proof of concept available
Recorded 2021-09-15 03:11:41 UTC · GitHub
Weaknesses (CWE)
-
Out-of-bounds Write
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Metasploit | https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/browser/chrome_cve_2021_21220_v8_insufficient_validation.rb | Apr 28, 2025 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2021-09-15 03:11:41 UTC · 9 stars
metasploit · Created Unknown
Metasploit module for CVE-2021-21220
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
15:02 UTC about 1 year ago15:02 UTC · about 1 year ago
Metasploit module available
Exploit module available
-
00:00 UTC over 4 years ago00:00 UTC · over 4 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
03:11 UTC almost 5 years ago03:11 UTC · almost 5 years ago
Public PoC available
Public proof-of-concept code published
-
00:00 UTC about 5 years ago00:00 UTC · about 5 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC over 5 years ago00:00 UTC · over 5 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2021-21220
{
"cve_id": "CVE-2021-21220",
"title": "Insufficient validation of untrusted input in V8 in Google Chrome prior to 89...",
"affected_vendor": "Google",
"affected_product": "Chrome",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}