CVE-2019-8591: A type confusion issue was addressed with improved memory handling

Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified

What, why and how

A type confusion issue was addressed with improved memory handling. This issue is fixed in iOS 12.3, macOS Mojave 10.14.5, tvOS 12.3, watchOS 5.2.1. An application may be able to cause unexpected system termination or write kernel memory.

What

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 cause the confidentiality, integrity or availability impact described by the vendor.

What

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

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.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

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') → cause the confidentiality, integrity or availability impact described by the vendor
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:N/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.CNoneConfidentiality impact: No direct loss is represented by this metric.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: The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.

UnauthenticatedCWE-843

Official authority intelligence

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

ENISA EUVD · EUVD-2019-17981Official EUVD mapping

0 linked advisory records.

Official EUVD record ↗

CERT-FR · French · CERTFR-2019-AVI-204Multiples vulnérabilités dans les produits Apple

.cve.org/CVERecord?id=CVE-2019-8576 Référence CVE CVE-2019-8577 https://www.cve.org/CVERecord?id=CVE-2019-8577 Référence CVE CVE-2019-8583 https://www.cve.org/CVERecord?id=CVE-2019-8583 Référence CVE CVE-2019-8584 https://www.cve.org/CVERecord?id=CVE-2019-8584 Référence CVE CVE-2019-8585 https://www.cve.org/CVERecord?id=CVE-2019-8585 Référence CVE CVE-2019-8586 https://www.cve.org/CVERecord?id=CVE-2019-8586 Référence CVE CVE-2019-8587 https://www.cve.org/CVERecord?id=CVE-2019-8587 Référence CVE CVE-2019-8589 https://www.cve.org/CVERecord?id=CVE-2019-8589 Référence CVE CVE-2019-8590 https://www.cve.org/CVERecord?id=CVE-2019-8590 Référence CVE CVE-2019-8591 https://www.cve.org/CVERecord?id=CVE-2019-8591 Référence CVE CVE-2019-8592 https://www.cve.org/CVERecord?id=CVE-2019-8592 Référence CVE CVE-2019-8593 https://www.cve.org/CVERecord?id=CVE-2019-8593 Référence CVE CVE-2019-8594 https://www.cve.org/CVERecord?id=CVE-2019-8594 Référence CVE CVE-2019-8595 https://www.cve.org/CVERecord?id=CVE-2019-8595 Référence CVE CVE-2019-8596 https://www.cve.org/CVERecord?id=CVE-2019-8596 Référence CVE CVE-2019-8597 https://www.cve.org/CVERecord?id=CVE-2019-8597 Référence CVE CVE-2019-8598 https://www.cve.org/CVERecord?id=CVE-2019-8598 Référence CVE CVE-2019-8599 https://www.cve.org/CVERecord?id=CVE-2019-8599 Ré

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2019-003317複数の Apple 製品における脆弱性に対するアップデート

Apple から各製品向けのアップデートが公開されました。

Official advisory ↗

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: unspecified < iOS 12.3
macOS: unspecified < macOS Mojave 10.14.5
tvOS: unspecified < tvOS 12.3
watchOS: unspecified < watchOS 5.2.1
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.

Official vendor articles4 stored documents

Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.

About the security content of iOS 12.3 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 16 Oct 2026Apple Store Mac iPad iPhone Watch Vision AirPods Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","text":"
About the security content of macOS Mojave 10.14.5, Security Update 2019-003 High Sierra, Security Update 2019-003 Sierra - Apple Support →Original publisher ↗Searchable text snapshot · Captured 16 Oct 2026Apple Store Mac iPad iPhone Watch Vision AirPods Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","text":"
About the security content of tvOS 12.3 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 16 Oct 2026Apple Store Mac iPad iPhone Watch Vision AirPods Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","text":"
About the security content of watchOS 5.2.1 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 16 Oct 2026Apple Store Mac iPad iPhone Watch Vision AirPods Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","text":"

Evidence and provenance

Published 18 Dec 2019 · Last source change 4 Aug 2024, 21:24 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 2026-09-01

European sourceENISA EUVD · EUVD-2019-17981

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceNIST NVD

NVD statusNVD modified after enrichment

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

Material change intelligence

What changed after publication

View recent updates ↗

1 Sep 2026, 02:42 UTC
ENISA EUVD mappingEUVD-2019-17981 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2019-17981"}
ENISA EUVD ↗
4 Aug 2024, 21:24 UTC
Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: support.apple.com/HT210118; added vendor advisory: support.apple.com/HT210119; 2 further additions.
Before
no authoritative guidance recorded
After
vendor advisory: support.apple.com/HT210118 · vendor advisory: support.apple.com/HT210119 · vendor advisory: support.apple.com/HT210120 · 1 more references
support.apple.com ↗
4 Aug 2024, 21:24 UTC
SeveritySeverity changed from Unknown to High.
Before
Unknown
After
High
NIST NVD ↗
4 Aug 2024, 21:24 UTC
CVSS scoreCVSS score changed from not recorded to 7.1 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H).
Before
not recorded
After
7.1 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H)
NIST NVD ↗
4 Aug 2024, 21:24 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2019-12-18CVE published

ENISA EUVD · EUVD-2019-17981↗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.

A type confusion issue was addressed with improved memory handling

Published severity in operational context

Evidence used

Compensating controls

Verification

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

ENISA European Vulnerability Database

EUVD-2019-17981