CASCACascade Atlas

Evidence dossier

CVE-2021-1870

CVE-2021-1870

64.4–85.1Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

State
PUBLISHED
Published
Apr 2, 2021
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS7.92%

2026-07-18 · v2026.06.15 · percentile 94.1%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

appleoriginal assertion
container

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

CISA KEVoriginal assertion
observed_exploitation

Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.079210000000; percentile 0.940730000000

Applicability

Cited product scope

Trace impact →
AppleiOS and iPadOS
[{"status": "affected", "version": "unspecified", "lessThan": "14.4", "versionType": "custom"}]unknown
ApplemacOS
[{"status": "affected", "version": "unspecified", "lessThan": "11.2", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:webkitgtk:webkitgtk:*:*:*:*:*:*:*:*; end excluding 2.30.6supported
Unknown vendorUnknown product
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*; end excluding 14.4supported
Unknown vendorUnknown product
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*; end excluding 14.4supported
Unknown vendorUnknown product
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*; start including 11.0.1; end excluding 11.2supported
Unknown vendorUnknown product
cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*; start including 10.15; end excluding 10.15.7supported
Unknown vendorUnknown product
cpe:2.3:o:apple:mac_os_x:10.15.7:-:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:apple:mac_os_x:10.15.7:supplemental_update:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*supported

Assessments

CVSS by origin

9.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8
134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
CISA-ADPCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.