CVE-2025-24189: Apple Safari Buffer Overflow Vulnerability

CVE-2025-24189 Overview

CVE-2025-24189 is a memory corruption vulnerability affecting Apple's WebKit browser engine across multiple Apple platforms and products. The vulnerability exists due to improper memory handling when processing maliciously crafted web content, which can lead to memory corruption. This issue was addressed by Apple with improved checks in their affected software components.

Critical Impact

Processing maliciously crafted web content may lead to memory corruption, potentially allowing attackers to execute arbitrary code or cause denial of service conditions across multiple Apple platforms including Safari, iOS, macOS, and other Apple operating systems.

Affected Products

• Apple Safari (versions prior to 18.3)
• Apple iOS and iPadOS (versions prior to 18.3)
• Apple macOS Sequoia (versions prior to 15.3)
• Apple tvOS (versions prior to 18.3)
• Apple visionOS (versions prior to 2.3)
• Apple watchOS (versions prior to 11.3)

Discovery Timeline

• 2025-05-19 - CVE-2025-24189 published to NVD
• 2025-11-04 - Last updated in NVD database

Technical Details for CVE-2025-24189

Vulnerability Analysis

This vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), indicating a memory corruption issue that occurs when the software performs operations on a memory buffer but can read from or write to a memory location outside the intended boundary of the buffer.

When the WebKit engine processes specially crafted web content, it fails to properly validate certain memory operations, leading to out-of-bounds memory access. This memory corruption can result in unpredictable behavior, application crashes, or potentially enable an attacker to execute arbitrary code in the context of the affected application.

The vulnerability requires user interaction—specifically, a victim must visit a malicious website or be tricked into loading malicious web content through Safari or any application utilizing the WebKit rendering engine. Given the ubiquity of WebKit across Apple's ecosystem, this vulnerability has a broad attack surface spanning desktop, mobile, wearable, and AR/VR platforms.

Root Cause

The root cause of CVE-2025-24189 lies in insufficient input validation and boundary checks within the WebKit rendering engine when handling specific types of web content. The vulnerability occurs because the affected code path does not properly verify memory boundaries before performing read or write operations, allowing crafted input to trigger memory corruption conditions.

Apple addressed this issue with "improved checks," indicating that additional validation logic was implemented to ensure memory operations remain within expected boundaries when processing potentially malicious web content.

Attack Vector

The attack vector for this vulnerability is network-based and requires user interaction. An attacker would typically exploit this vulnerability through the following scenario:

1. The attacker crafts malicious web content designed to trigger the memory corruption condition
2. The victim is lured to visit a malicious website or is served the malicious content through compromised advertising networks or other web-based delivery mechanisms
3. When the victim's browser (Safari) or WebKit-enabled application renders the malicious content, the memory corruption occurs
4. Depending on the exploitation technique, this could lead to code execution, information disclosure, or denial of service

The vulnerability can be triggered through any WebKit-based application across Apple's product line, making cross-platform exploitation feasible for attackers targeting the Apple ecosystem.

Detection Methods for CVE-2025-24189

Indicators of Compromise

• Unexpected Safari or WebKit-related application crashes with memory corruption signatures
• System logs showing abnormal memory allocation patterns from browser processes
• Suspicious network connections to unknown domains prior to application crashes
• Core dump files indicating out-of-bounds memory access in WebKit-related processes

Detection Strategies

• Monitor for unusual browser process behavior including unexpected memory consumption spikes
• Implement web filtering to block known malicious domains associated with WebKit exploitation
• Deploy endpoint detection solutions capable of identifying memory corruption exploitation attempts
• Analyze crash reports for WebKit-related memory corruption patterns (CWE-119 signatures)

Monitoring Recommendations

• Enable and review system crash logs for Safari and other WebKit-based applications regularly
• Implement network traffic analysis to detect potential exploit delivery attempts
• Configure SentinelOne agents to monitor for suspicious browser process behavior
• Set up alerting for multiple WebKit-related crashes from similar user populations

How to Mitigate CVE-2025-24189

Immediate Actions Required

• Update Safari to version 18.3 or later immediately
• Update iOS and iPadOS devices to version 18.3 or later
• Update macOS Sequoia to version 15.3 or later
• Update tvOS to version 18.3, visionOS to version 2.3, and watchOS to version 11.3 or later
• Enable automatic updates on all Apple devices to ensure timely security patch deployment

Patch Information

Apple has released security updates addressing this vulnerability across all affected platforms. The patches implement improved checks to prevent the memory corruption condition. For detailed information, refer to the following Apple Security Advisories:

• Apple Security Advisory #122066 - Safari 18.3
• Apple Security Advisory #122068 - visionOS 2.3
• Apple Security Advisory #122071 - iOS 18.3 and iPadOS 18.3
• Apple Security Advisory #122072 - macOS Sequoia 15.3
• Apple Security Advisory #122073 - watchOS 11.3
• Apple Security Advisory #122074 - tvOS 18.3

Additional technical discussion is available on the OpenWall OSS Security Discussion.

Workarounds

• Limit browsing to trusted websites until patches can be applied
• Use content blocking extensions to reduce exposure to potentially malicious web content
• Consider using alternative browsers temporarily on macOS if Safari cannot be immediately updated
• Implement network-level web filtering to block known exploit delivery infrastructure

# Check current Safari version on macOS
/usr/bin/defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString

# Check current iOS/iPadOS version
# Navigate to: Settings > General > About > Software Version

# Enable automatic updates on macOS
sudo softwareupdate --schedule on