CVE-2019-8657: An out-of-bounds read was addressed with improved input validation

Recommended actionWithin 7 days

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

Fix not verified

What, why and how

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 12.4, macOS Mojave 10.14.6, tvOS 12.4, watchOS 5.3. Parsing a maliciously crafted office document may lead to an unexpected application termination or arbitrary code execution.

What

Why

The product reads data past the end, or before the beginning, of the intended buffer.

How

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

What

Why

The product reads data past the end, or before the beginning, of the intended buffer.

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: a network path → Out-of-bounds Read → execute code or commands in the affected security context
Attack surface: Network
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-125 ↗
CWE-125: Out-of-bounds Read. The product reads data past the end, or before the beginning, of the intended buffer.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:N/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.
AVNetworkAttack vector: The vulnerable component can be reached over a network.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.

NetworkUnauthenticatedRemote code executionCWE-125

Official authority intelligence

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

ENISA EUVD · EUVD-2019-18047Official EUVD mapping

0 linked advisory records.

Official EUVD record ↗

CERT-FR · French · CERTFR-2019-AVI-356Multiples vulnérabilités dans les produits Apple

cve.org/CVERecord?id=CVE-2019-13118 Référence CVE CVE-2019-8624 https://www.cve.org/CVERecord?id=CVE-2019-8624 Référence CVE CVE-2019-8641 https://www.cve.org/CVERecord?id=CVE-2019-8641 Référence CVE CVE-2019-8644 https://www.cve.org/CVERecord?id=CVE-2019-8644 Référence CVE CVE-2019-8646 https://www.cve.org/CVERecord?id=CVE-2019-8646 Référence CVE CVE-2019-8647 https://www.cve.org/CVERecord?id=CVE-2019-8647 Référence CVE CVE-2019-8648 https://www.cve.org/CVERecord?id=CVE-2019-8648 Référence CVE CVE-2019-8649 https://www.cve.org/CVERecord?id=CVE-2019-8649 Référence CVE CVE-2019-8656 https://www.cve.org/CVERecord?id=CVE-2019-8656 Référence CVE CVE-2019-8657 https://www.cve.org/CVERecord?id=CVE-2019-8657 Référence CVE CVE-2019-8658 https://www.cve.org/CVERecord?id=CVE-2019-8658 Référence CVE CVE-2019-8659 https://www.cve.org/CVERecord?id=CVE-2019-8659 Référence CVE CVE-2019-8660 https://www.cve.org/CVERecord?id=CVE-2019-8660 Référence CVE CVE-2019-8661 https://www.cve.org/CVERecord?id=CVE-2019-8661 Référence CVE CVE-2019-8662 https://www.cve.org/CVERecord?id=CVE-2019-8662 Référence CVE CVE-2019-8663 https://www.cve.org/CVERecord?id=CVE-2019-8663 Référence CVE CVE-2019-8665 https://www.cve.org/CVERecord?id=CVE-2019-8665 Référence CVE CVE-2019-8666 https://www.cve.org/CVERecord?id=CVE-2019-8666 Ré

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2019-006634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 12.4
macOS: unspecified < macOS Mojave 10.14.6
tvOS: unspecified < tvOS 12.4
watchOS: unspecified < watchOS 5.3
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. If business-safe, reduce exposure to the affected interface and allow only trusted sources 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 12.4 - 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 10.14.6, Security Update 2019-004 High Sierra, Security Update 2019-004 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 12.4 - 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 5.3 - 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":"

Evidence and provenance

Published 18 Dec 2019 · Last source change 4 Aug 2024, 21:24 UTC · CWE-125 · Out-of-bounds Read

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-2019-18047

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-2019-18047 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2019-18047"}
ENISA EUVD ↗
4 Aug 2024, 21:24 UTC
Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: support.apple.com/HT210346; added vendor advisory: support.apple.com/HT210348; 2 further additions.
Before
no authoritative guidance recorded
After
vendor advisory: support.apple.com/HT210346 · vendor advisory: support.apple.com/HT210348 · vendor advisory: support.apple.com/HT210351 · 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 8.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).
Before
not recorded
After
8.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/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-2019-18047↗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.

An out-of-bounds read was addressed with improved input validation

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-2019-18047