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Vulnerabilities

Vulnerability · CVE-2021-1789

Apple Multiple Products Type Confusion Vulnerability

Published Apr 2, 2021 · catalog updated Jun 16, 2026 · Apple Multiple Products

Patch now

CVE-2021-1789 is in the CISA known-exploited catalog, due May 25, 2022. Confirm Apple Multiple Products against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Severity
High8.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
13.98%
Remediation
Remediation guidance
Affected products
cpe apple/ipados · cpe apple/iphone os · cpe apple/mac os x · cpe fedoraproject/fedora · cpe webkitgtk/webkitgtk · vendor Apple Multiple Products

A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

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.

  • cpe apple/ipadosversion unspecified
  • cpe apple/iphone osversion unspecified
  • cpe apple/mac os x10.14.6
  • cpe fedoraproject/fedora32
  • cpe webkitgtk/webkitgtkversion unspecified
  • vendor Apple Multiple Productsversion unspecified

How to fix CVE-2021-1789

What to do

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

Should you patch?

CVE-2021-1789 is in the CISA known-exploited catalog, due May 25, 2022. Confirm Apple Multiple Products against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Compare what you have installed with apple/mac os x 10.14.6. Apply updates per vendor instructions.

What should an analyst verify?

CWE-843: Access of Resource Using Incompatible Type (Type Confusion). EPSS 13.98%. 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. Apr 2, 2021 · Catalog

    Detected

    A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

  2. May 4, 2022 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. May 25, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Sources

  • CISA KEVConfirmed exploitationCVE-2021-1789

    A type confusion issue affecting multiple Apple products allows processing of maliciously crafted web content, leading to arbitrary code execution.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2021-1789

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-1789

    30-day exploitation probability 14.0%

    first.org
  • NIST NVDVulnerability recordCVE-2021-1789

    A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web co

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2021-1789

    A type confusion issue affecting multiple Apple products allows processing of maliciously crafted web content, leading to arbitrary code execution.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.