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Vulnerabilities

Vulnerability · CVE-2021-1765

Apple macOS iframe Sandbox Enforcement Vulnerability

Published Aug 16, 2021 · catalog updated Aug 16, 2021 · Apple MacOS X

Patch now

CVE-2021-1765 is in the CISA known-exploited catalog. Confirm Apple MacOS X against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Unknown—
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
1.41%
Remediation
Remediation guidance
Affected products
vendor Apple MacOS X

This issue was addressed with improved iframe sandbox enforcement. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. Maliciously crafted web content may violate iframe sandboxing policy.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Apple MacOS Xversion unspecified

How to fix CVE-2021-1765

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2021-1765 is in the CISA known-exploited catalog. Confirm Apple MacOS X against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

What should an analyst verify?

No weakness class is stored. EPSS 1.41%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 16, 2021 · VulnCheck KEV

    Detected

    This issue was addressed with improved iframe sandbox enforcement. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. Maliciously crafted web content may violate iframe sandboxing policy.

  2. Aug 16, 2021 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Sources

  • CVE.orgVulnerability recordCVE-2021-1765

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-1765

    30-day exploitation probability 1.4%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-2021-1765

    This issue was addressed with improved iframe sandbox enforcement. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave. Maliciously crafted web content may violate iframe sandboxing policy.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.