CASCACascade Atlas

Evidence dossier

CVE-2021-30900

CVE-2021-30900

64.1–82.8Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.

State
PUBLISHED
Published
Aug 24, 2021
Updated
Oct 21, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS5.20%

2026-07-18 · v2026.06.15 · percentile 91.6%

Source stateConflict visible

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

Source comparison

Who said what

appleoriginal assertion
container

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

CISA KEVoriginal assertion
observed_exploitation

Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.052040000000; percentile 0.915590000000

Applicability

Cited product scope

Trace impact →
AppleiOS and iPadOS
[{"status": "affected", "version": "unspecified", "lessThan": "15.1", "versionType": "custom"}]unknown
AppleiOS and iPadOS
[{"status": "affected", "version": "unspecified", "lessThan": "14.8", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*; end excluding 14.8.1supported
Unknown vendorUnknown product
cpe:2.3:o:apple:ipados:15.0:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*; end excluding 14.8.1supported
Unknown vendorUnknown product
cpe:2.3:o:apple:iphone_os:15.0:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*; end excluding 11.6.1supported

Assessments

CVSS by origin

7.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:M/Au:N/C:C/I:C/A:C
7.8
134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS 3.1 · role SecondaryCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8
CISA-ADPCVSS 3.1 · role unknownCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.