Cyber Resilience

CVE-2021-30869

HighCISA KEVActive ExploitationEUVD Exploited

Published: 24 August 2021

Published
24 August 2021
Modified
23 October 2025
KEV Added
03 November 2021
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0172 82.8th percentile
Risk Priority 37 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-30869 is a high-severity Type Confusion (CWE-843) vulnerability in Apple Mac Os X. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 17.2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SC-39 (Process Isolation).

Deeper analysis

A type confusion vulnerability, tracked as CVE-2021-30869 and assigned CWE-843, was present in multiple Apple operating systems. The flaw was addressed through improved state handling and affected iOS prior to 12.5.5 and 14.4, iPadOS prior to 14.4, macOS Big Sur prior to 11.2, and earlier Catalina and Mojave releases addressed by the listed 2021 security updates. The CVSS 3.1 score of 7.8 reflects local attack vector, low complexity, and no privileges required.

A malicious application running on an affected device can exploit the issue to achieve arbitrary code execution with kernel privileges. The attack requires user interaction such as opening a crafted file or application but needs no prior authentication.

Apple security advisories for the listed updates state that the vulnerability has been resolved in the specified iOS, iPadOS, and macOS releases. The vendor notes that it is aware of reports indicating an exploit for this issue exists in the wild.

EU & UK References

Vulnerability details

A type confusion issue was addressed with improved state handling. This issue is fixed in iOS 12.5.5, iOS 14.4 and iPadOS 14.4, macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, Security Update 2021-006 Catalina. A malicious…

more

application may be able to execute arbitrary code with kernel privileges. Apple is aware of reports that an exploit for this issue exists in the wild.

CWE(s)
KEV Date Added
03 November 2021

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

apple
ipados
≤ 14.4
apple
iphone os
12.0 — 12.5.5 · 14.0 — 14.4
apple
mac os x
10.14.6, 10.15.7 · 10.14 — 10.14.6 · 10.15 — 10.15.6
apple
macos
11.0 — 11.2

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires timely installation of the vendor patches that eliminate the type-confusion flaw before a malicious application can exploit it.

prevent

Enforces process isolation boundaries that block a user-space application from reaching kernel memory objects via the type-confusion primitive.

prevent

Applies memory-protection mechanisms that detect or block the invalid type casts used to obtain kernel privileges.

References