Security readout for executives and security teams
Plain-English summary
This is a high-impact Chrome vulnerability in V8, Chrome’s JavaScript engine. A malicious web page could make vulnerable Chrome versions run attacker-controlled code inside the browser sandbox. Because CISA lists CVE-2021-21224 in KEV, treat old Chrome or Chromium builds as urgent exposure.
Executive priority
Prioritize remediation as high. Browser flaws are broadly exposed, require only user browsing activity, and this CVE is in CISA KEV. Focus first on unmanaged endpoints and systems running old Chromium packages.
Technical view
CVE-2021-21224 is a CWE-843 type confusion flaw in V8 affecting Google Chrome before 90.0.4430.85. CVSS 3.1 is 8.8: network exploitable, low complexity, no privileges, user interaction required. Sources describe arbitrary code execution inside the sandbox via crafted HTML.
Likely exposure
Exposure is most likely on unmanaged desktops, embedded Chromium-based applications, or Linux systems with outdated Chromium packages from 2021. Systems already updated beyond Chrome 90.0.4430.85 are unlikely to remain affected based on the provided sources.
Exploitation context
Active exploitation is supported by CISA KEV listing for CVE-2021-21224. The provided bundle does not include exploit details, observed campaign information, or evidence of sandbox escape. User interaction is required, such as loading attacker-controlled HTML.
Researcher notes
The source bundle establishes V8 type confusion, crafted HTML trigger, code execution inside sandbox, and KEV status. It does not provide root-cause details, proof-of-concept status, exploit mechanics, or confirmed sandbox escape evidence.
Mitigation direction
- Update Google Chrome to 90.0.4430.85 or later.
- Update Chromium packages through Debian, Gentoo, Fedora, or relevant vendor advisories.
- Check vendor guidance for Chromium-based applications bundling V8.
- Prioritize managed browser patch compliance across endpoints.
- Remove or isolate unsupported browser installations.
Validation and detection
- Inventory Chrome and Chromium versions across endpoints.
- Confirm no installed Chrome versions are earlier than 90.0.4430.85.
- Review Linux package advisory status for Chromium updates.
- Check EDR or asset data for legacy browser launches.
- Document any bundled Chromium applications for vendor follow-up.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-843: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-21224 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://chromereleases.googleblog.com/2021/04/stable-channel-update-for-desktop_20.htmlCVE reference · x_refsource_MISC
- https://crbug.com/1195777CVE reference · x_refsource_MISC
- DSA-4906CVE reference · vendor-advisory, x_refsource_DEBIAN
- GLSA-202104-08CVE reference · vendor-advisory, x_refsource_GENTOO
- FEDORA-2021-c3754414e7CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-ff893e12c5CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-35d2bb4627CVE reference · vendor-advisory, x_refsource_FEDORA
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21224CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.