CVE-2019-8540

MEDIUM

iPhone OS < 12.2 - Unauthenticated Memory Layout Exposure via Improper Initialization

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2019-8540. PoCs published by maldiohead.

AI-analyzed exploit summary This PoC exploits a kernel stack info leak in macOS and iOS via the `exportObjectToClient` function in IOKit. It demonstrates leaking 4 bytes of kernel stack data by forcing a type conversion from `io_object_t` (8 bytes) to `mach_port_name_t` (4 bytes).

Description

A memory initialization issue was addressed with improved memory handling. This issue is fixed in iOS 12.2, macOS Mojave 10.14.4, tvOS 12.2, watchOS 5.2. A malicious application may be able to determine kernel memory layout.

Exploits (1)

nomisec WORKING POC 42 stars
by maldiohead · poc
https://github.com/maldiohead/CVE-2019-8540

This PoC exploits a kernel stack info leak in macOS and iOS via the `exportObjectToClient` function in IOKit. It demonstrates leaking 4 bytes of kernel stack data by forcing a type conversion from `io_object_t` (8 bytes) to `mach_port_name_t` (4 bytes).

Classification
Working Poc 90%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: macOS <= 10.14.3, iOS < 12.2
No auth needed
Prerequisites: Access to a vulnerable macOS or iOS device
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (4)

Core 4
Core References
Vendor Advisory x_refsource_misc
https://support.apple.com/HT209599
Vendor Advisory x_refsource_misc
https://support.apple.com/HT209601
Vendor Advisory x_refsource_misc
https://support.apple.com/HT209600
Vendor Advisory x_refsource_misc
https://support.apple.com/HT209602

Scores

CVSS v3 5.5
EPSS 0.0159
EPSS Percentile 72.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Details

CWE
CWE-665
Status published
Products (4)
apple/iphone_os < 12.2
apple/mac_os_x < 10.14.4
apple/tvos < 12.2
apple/watchos < 5.2
Published Dec 18, 2019
Tracked Since Feb 18, 2026