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CVE Record

CVE-2021-30538: Insufficient policy enforcement in content security policy in Google Chrome prior to 91.0.4472.77 allowed a...

Insufficient policy enforcement in content security policy in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass content security policy via a crafted HTML page.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-30538 is a Google Chrome flaw where a malicious web page could bypass browser content security policy protections. Google fixed it before Chrome 91.0.4472.77. The main business risk is users running old or unmanaged Chrome installations, where web-based protections may not behave as intended.

Executive priority

Treat this as a normal-priority browser patching item unless legacy Chrome remains in production. The vulnerability is old and not KEV-listed in the supplied data, but browsers are high-exposure software and stale versions create avoidable web risk.

Technical view

The CVE describes insufficient policy enforcement in Chrome's content security policy handling before 91.0.4472.77. A remote attacker could use crafted HTML to bypass CSP. The bundle does not provide CVSS, CWE, detailed impact, or public technical root-cause details.

Likely exposure

Exposure is limited to Chrome installations older than 91.0.4472.77 and downstream packaged browsers covered by applicable vendor advisories. In 2026, the most likely exposed assets are legacy desktops, unmanaged endpoints, frozen images, or systems excluded from normal browser updates.

Exploitation context

The provided sources do not show CISA KEV listing, active exploitation, or public weaponization. The vulnerability is remotely reachable through web content, but the bundle only supports describing it as a CSP bypass via crafted HTML, not confirmed exploitation in the wild.

Researcher notes

The public bundle is sparse: no CVSS, CWE, exploit status, or detailed bug analysis is provided. Keep assessment constrained to Chrome before 91.0.4472.77 and vendor package advisories. Avoid assuming broader CSP impact without site-specific testing and vendor documentation.

Mitigation direction

  • Update Chrome to 91.0.4472.77 or a current supported release.
  • Apply applicable Gentoo or Fedora browser package updates where those distributions are used.
  • Check Google and distribution vendor guidance for any environment-specific remediation.
  • Remove or isolate systems that cannot receive supported browser updates.

Validation and detection

  • Verify Chrome version is 91.0.4472.77 or later across managed endpoints.
  • Review software inventory for legacy Chrome installations below the fixed version.
  • Confirm Linux package managers show relevant Gentoo or Fedora advisories applied.
  • Check endpoint management policies enforce automatic browser updates.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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CVE-2021-30538 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
6Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
GoogleChromeunspecifiedListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.