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CVE Record

CVE-2021-30539: 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 analysisunknown

Security readout for executives and security teams

Plain-English summary

This Chrome flaw could let a malicious web page bypass Content Security Policy, a browser protection that limits risky web content. Business risk mainly affects endpoints still running Chrome older than 91.0.4472.77 or affected distro packages. Sources provide no CVSS score or active exploitation evidence.

Executive priority

Treat as a hygiene-driven browser update issue unless old Chrome builds remain in production. The business urgency rises for unmanaged endpoints or environments where users browse untrusted sites. Evidence is insufficient to justify claims of active exploitation or critical severity.

Technical view

CVE-2021-30539 is insufficient policy enforcement in Chrome's Content Security Policy implementation. Prior to 91.0.4472.77, a remote attacker could bypass CSP using crafted HTML. Public details are sparse; the source bundle names no CWE, no CVSS vector, and no technical root cause beyond CSP enforcement failure.

Likely exposure

Exposure is most likely browser fleets with Chrome below 91.0.4472.77, and Linux systems receiving Chrome or Chromium through Gentoo or Fedora packages. Modern auto-updated browsers are less likely exposed, but unmanaged endpoints, gold images, kiosks, and legacy VDI images should be checked.

Exploitation context

The provided sources say the issue can be triggered remotely through a crafted HTML page. CISA KEV is false in the bundle, and no cited source states active exploitation. The private Chromium bug link may limit public exploitability detail.

Researcher notes

Public data identifies a CSP bypass through crafted HTML, but does not expose root-cause detail, CWE, CVSS, or exploit status. Use the Chromium bug and vendor advisories as reference points, but avoid assuming impact beyond CSP bypass in pre-91.0.4472.77 Chrome.

Mitigation direction

  • Update Chrome to 91.0.4472.77 or later.
  • Apply Gentoo or Fedora vendor package updates where those distributions are used.
  • Check vendor guidance for any additional Chrome or Chromium remediation notes.
  • Prioritize unmanaged browsers, kiosks, VDI images, and stale base images.

Validation and detection

  • Inventory Chrome and Chromium versions across managed endpoints.
  • Confirm no systems remain below Chrome 91.0.4472.77.
  • Review Gentoo and Fedora package advisory compliance for affected hosts.
  • Verify browser auto-update and endpoint management policies are functioning.
Prepared
Confidence
medium
Sources
6

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-2021-30539 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.