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Full vulnerability report · 2021
CVE-2021-30869High confidence

Apple iOS, iPadOS, and macOS Type Confusion Vulnerability

Apple · iOS, iPadOS, and macOS

7.8HighCVSS 3.1
Recommended action
Protect now

CISA confirms exploitation in the wild and lists 2021-11-17 as the remediation due date.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Critical, raised one band.upgradedsince 3 Nov 2021

Evidence used

  • CISA confirms exploitation in the wild.
  • EPSS is 4.13% for the current model date.

Compensating controls

  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Apple iOS, iPadOS, and macOS and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-17786

CISA KEV mirrored by ENISA

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 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.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 3 Nov 2021. Evidence sources: cisa_kev.
ENISA score
7.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionProtect now

CISA confirms exploitation in the wild and lists 2021-11-17 as the remediation due date.

Fix not verified
01

What, why and how

Apple iOS, iPadOS, and macOS contain a type confusion vulnerability in the XNU which may allow a malicious application to execute code with kernel privileges.

What

Apple iOS, iPadOS, and macOS contain a type confusion vulnerability in the XNU which may allow a malicious application to execute code with kernel privileges.

Why

The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.

What

Apple iOS, iPadOS, and macOS contain a type confusion vulnerability in the XNU which may allow a malicious application to execute code with kernel privileges.

Why

The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

How

An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2021-11-03.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Access of Resource Using Incompatible Type ('Type Confusion') → execute code or commands in the affected security context
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-843 ↗

CWE-843: Access of Resource Using Incompatible Type ('Type Confusion'). The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
UnauthenticatedRemote code executionCWE-843CISA KEV
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2021-17786Known-exploited evidence recorded

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 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.

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20210825Security Bulletin 25 Aug 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 25 Aug 2021, published on 25 August 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-732Multiples vulnérabilités dans les produits Apple

De multiples vulnérabilités ont été découvertes dans les produits Apple. Elles permettent à un attaquant de provoquer une exécution de code arbitraire.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-021188複数のアップル製品における型の取り違えに関する脆弱性

iPadOS、iOS、Apple Mac OS X 等複数のアップル製品には、型の取り違えに関する脆弱性が存在します。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-5398Apple 제품 보안 업데이트 권고

macOS 카탈리나에서 타입 혼동(Type Confusion)으로 발생하는 임의코드실행 취약점(CVE-2021-30869) [2]

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
  • iOS and iPadOS: unspecified < 14.4
  • macOS: unspecified < 11.2, unspecified < 12.5, unspecified < 2021
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 24 Aug 2021 · Last source change 21 Oct 2025, 23:25 UTC · CWE-843 · Access of Resource Using Incompatible Type ('Type Confusion')

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-17786
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    unspecified < 14.4; unspecified < 11.2; unspecified < 12.5; unspecified < 2021 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    iOS and iPadOS: unspecified < 14.4; macOS: unspecified < 11.2, unspecified < 12.5, unspecified < 2021 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
ENISA EUVD · EUVD-2021-17786↗CISA KEV record↗CVE authority or vendor reference↗Vendor advisory↗Vendor advisory↗Vendor advisory↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
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