CVE-2025-43237: Apple macOS Buffer Overflow Vulnerability

CVE-2025-43237 Overview

CVE-2025-43237 is an out-of-bounds write vulnerability (CWE-787) affecting Apple macOS. The vulnerability arises from insufficient bounds checking, allowing a malicious application to write data beyond the boundaries of allocated memory buffers. This memory corruption issue was addressed by Apple with improved bounds checking in macOS Sequoia 15.6. Successful exploitation could allow an application to cause unexpected system termination, potentially leading to denial of service conditions or, in more severe scenarios, arbitrary code execution.

Critical Impact

This out-of-bounds write vulnerability in macOS allows malicious applications to corrupt memory and cause system crashes. Given the network attack vector and no required user interaction, this poses a significant risk to macOS systems.

Affected Products

• Apple macOS (versions prior to macOS Sequoia 15.6)

Discovery Timeline

• 2025-07-30 - CVE-2025-43237 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-43237

Vulnerability Analysis

This vulnerability is classified as an out-of-bounds write (CWE-787), a memory corruption vulnerability that occurs when software writes data past the end or before the beginning of an intended memory buffer. In the context of macOS, this type of vulnerability can be particularly dangerous as it may allow attackers to overwrite critical system memory regions, potentially corrupting application state, causing system crashes, or enabling code execution in the context of the affected process.

The vulnerability can be exploited remotely over the network without requiring any privileges or user interaction, making it a significant threat to unpatched macOS systems. The impact extends across confidentiality, integrity, and availability, as successful exploitation could lead to information disclosure, unauthorized modifications, or complete system denial of service.

Root Cause

The root cause of CVE-2025-43237 is improper bounds checking when handling memory operations within macOS. When applications perform write operations, the system failed to properly validate that the destination buffer had sufficient capacity for the data being written. This oversight allowed write operations to exceed buffer boundaries, corrupting adjacent memory regions.

Apple addressed this vulnerability by implementing improved bounds checking to ensure that all write operations are constrained within the allocated memory boundaries, preventing out-of-bounds memory access.

Attack Vector

The attack vector for CVE-2025-43237 is network-based, meaning an attacker could potentially exploit this vulnerability remotely without requiring local access to the target system. A malicious application designed to trigger the out-of-bounds write condition could cause unexpected system termination, resulting in denial of service.

The exploitation scenario involves crafting input or conditions that cause the vulnerable code path to write data beyond allocated buffer limits. Since no authentication or user interaction is required, systems exposed to network traffic containing malicious payloads could be vulnerable to exploitation.

Detection Methods for CVE-2025-43237

Indicators of Compromise

• Unexpected system crashes or kernel panics on macOS systems
• Unusual memory access patterns in system logs
• Applications terminating unexpectedly with memory-related error codes
• Elevated crash frequency in system diagnostic reports

Detection Strategies

• Monitor macOS system logs for kernel panic events and memory corruption indicators
• Implement endpoint detection and response (EDR) solutions capable of identifying anomalous memory access patterns
• Deploy SentinelOne agents to detect exploitation attempts targeting memory corruption vulnerabilities
• Review crash reports in Console.app for patterns indicating out-of-bounds write attempts

Monitoring Recommendations

• Enable advanced crash reporting and analysis on macOS endpoints
• Configure SentinelOne to alert on behavioral indicators associated with memory corruption exploits
• Monitor for applications exhibiting unusual memory allocation patterns
• Implement network traffic analysis to detect potential exploitation payloads

How to Mitigate CVE-2025-43237

Immediate Actions Required

• Update all macOS systems to macOS Sequoia 15.6 or later immediately
• Review and audit installed applications for potential malicious software
• Implement application allowlisting to prevent unauthorized applications from executing
• Enable SentinelOne's behavioral AI protection to detect and block exploitation attempts

Patch Information

Apple has released a security update addressing this vulnerability in macOS Sequoia 15.6. System administrators should prioritize deployment of this update across all managed macOS endpoints. The security advisory with complete patch details is available from the Apple Security Advisory. Additional technical details can be found in the Full Disclosure Mailing List Post.

To apply the update:

1. Navigate to System Settings > General > Software Update
2. Download and install macOS Sequoia 15.6 or later
3. Restart the system when prompted to complete the installation

Workarounds

• Limit application installations to trusted sources (App Store and identified developers)
• Enable Gatekeeper and ensure it is configured to block applications from unidentified developers
• Implement network segmentation to limit exposure of vulnerable systems
• Deploy endpoint protection solutions like SentinelOne to detect and prevent exploitation attempts

# Verify current macOS version
sw_vers -productVersion

# Check for available updates via command line
softwareupdate --list

# Install all available updates
sudo softwareupdate --install --all --restart