CVE-2023-32387: Apple macOS Use-After-Free Vulnerability

CVE-2023-32387 Overview

CVE-2023-32387 is a use-after-free vulnerability affecting Apple macOS that was addressed with improved memory management. This memory corruption flaw allows remote attackers to potentially cause unexpected application termination or achieve arbitrary code execution on vulnerable systems without requiring user interaction or authentication.

Critical Impact

A remote attacker can exploit this use-after-free vulnerability to execute arbitrary code on affected macOS systems, potentially leading to complete system compromise without any user interaction.

Affected Products

• Apple macOS Ventura versions prior to 13.4
• Apple macOS Monterey versions prior to 12.6.6
• Apple macOS Big Sur versions prior to 11.7.7

Discovery Timeline

• June 23, 2023 - CVE-2023-32387 published to NVD
• November 4, 2025 - Last updated in NVD database

Technical Details for CVE-2023-32387

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption issue that occurs when a program continues to use a pointer after the memory it references has been freed. In the context of CVE-2023-32387, macOS fails to properly manage memory lifecycle, creating a condition where freed memory can be referenced by subsequent operations.

The use-after-free condition is particularly dangerous because the freed memory region may be reallocated for different data. When the original dangling pointer is dereferenced, it may now point to attacker-controlled data, enabling code execution. The network-accessible attack vector combined with no authentication requirements makes this vulnerability highly exploitable in enterprise environments.

Root Cause

The root cause of CVE-2023-32387 lies in improper memory management within macOS. Specifically, a memory object is freed but the pointer referencing that memory is not properly invalidated or nullified. Subsequent code paths continue to use this stale pointer, creating a use-after-free condition. Apple addressed this by implementing improved memory management practices to ensure proper handling of memory object lifecycles.

Attack Vector

The vulnerability can be exploited remotely over the network without requiring any user interaction or prior authentication. An attacker can craft malicious network traffic or content that triggers the use-after-free condition in a vulnerable macOS component. Upon successful exploitation, the attacker gains the ability to execute arbitrary code with the privileges of the affected process, potentially leading to full system compromise.

The exploitation flow typically involves:

1. Triggering the deallocation of a memory object while references still exist
2. Allocating new memory that occupies the freed region with attacker-controlled content
3. Causing the application to access the dangling pointer, which now references malicious data
4. Achieving code execution through controlled memory corruption

For detailed technical analysis, refer to the Talos Intelligence Vulnerability Report TALOS-2023-1717.

Detection Methods for CVE-2023-32387

Indicators of Compromise

• Unexpected application crashes or terminations on macOS systems, particularly in network-facing services
• Abnormal memory access patterns or memory corruption errors in system logs
• Suspicious network connections or traffic patterns targeting macOS endpoints
• Anomalous process behavior following network activity, including unexpected child processes

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions capable of monitoring memory access patterns and detecting use-after-free exploitation attempts
• Implement network intrusion detection systems (IDS) to identify potential exploitation traffic targeting this vulnerability
• Monitor for heap spray indicators and suspicious memory allocation patterns that may precede use-after-free exploitation
• Enable and analyze crash reports on macOS endpoints to identify potential exploitation attempts

Monitoring Recommendations

• Configure centralized logging for macOS endpoints to capture application crashes and memory errors
• Implement real-time alerting for abnormal process behavior or unexpected code execution
• Monitor software inventory to identify systems running vulnerable macOS versions
• Track network traffic for anomalous patterns targeting macOS services

How to Mitigate CVE-2023-32387

Immediate Actions Required

• Immediately update all macOS Big Sur systems to version 11.7.7 or later
• Immediately update all macOS Monterey systems to version 12.6.6 or later
• Immediately update all macOS Ventura systems to version 13.4 or later
• Prioritize patching for internet-facing or network-accessible macOS systems
• Conduct an inventory assessment to identify all affected systems across the organization

Patch Information

Apple has released security updates addressing this vulnerability across all affected macOS versions. The patches implement improved memory management to prevent the use-after-free condition. Organizations should apply these updates as a priority given the network-accessible attack vector and potential for arbitrary code execution.

For detailed patch information, refer to the following Apple Security Advisories:

• Apple Support Article HT213758 - macOS Big Sur 11.7.7
• Apple Support Article HT213759 - macOS Monterey 12.6.6
• Apple Support Article HT213760 - macOS Ventura 13.4

Workarounds

• Implement network segmentation to limit exposure of vulnerable macOS systems to untrusted networks
• Deploy host-based firewalls to restrict unnecessary network access to macOS endpoints
• Enable macOS security features including System Integrity Protection (SIP) and Gatekeeper
• Consider temporary isolation of systems that cannot be immediately patched from network access

# Check current macOS version
sw_vers -productVersion

# Verify System Integrity Protection status
csrutil status

# Check for available software updates
softwareupdate --list