CVE-2025-30427: Apple Safari Use-After-Free Vulnerability

CVE-2025-30427 Overview

CVE-2025-30427 is a use-after-free vulnerability affecting Apple Safari and related Apple operating systems. The vulnerability exists in the WebKit browser engine's memory management implementation, where improper handling of memory can lead to a use-after-free condition when processing maliciously crafted web content. This vulnerability falls under CWE-416 (Use After Free), a memory corruption flaw that occurs when a program continues to use memory after it has been freed.

Critical Impact

Processing maliciously crafted web content may lead to an unexpected Safari crash, causing denial of service conditions across multiple Apple platforms including iOS, macOS, iPadOS, tvOS, and visionOS.

Affected Products

• Apple Safari versions prior to 18.4
• Apple iOS versions prior to 18.4
• Apple iPadOS versions prior to 18.4 and 17.7.6
• Apple macOS Sequoia versions prior to 15.4
• Apple tvOS versions prior to 18.4
• Apple visionOS versions prior to 2.4

Discovery Timeline

• March 31, 2025 - CVE-2025-30427 published to NVD
• November 3, 2025 - Last updated in NVD database

Technical Details for CVE-2025-30427

Vulnerability Analysis

This vulnerability represents a use-after-free memory corruption issue in Apple's WebKit rendering engine, which powers Safari and web content across all Apple platforms. Use-after-free vulnerabilities occur when an application attempts to access memory that has already been deallocated, leading to undefined behavior.

In this case, the flaw manifests when the browser processes specially crafted web content that triggers improper memory management sequences. When exploited, the vulnerability causes the Safari browser to crash unexpectedly. While the immediate impact is limited to denial of service (causing application crashes), use-after-free vulnerabilities in browser engines can potentially be chained with other techniques for more severe impacts in certain scenarios.

The vulnerability affects the core web rendering infrastructure shared across Apple's ecosystem, making it particularly widespread as it impacts iPhone, iPad, Mac, Apple TV, and Vision Pro devices.

Root Cause

The root cause of CVE-2025-30427 lies in WebKit's memory management subsystem. During the processing of certain web content, the browser engine fails to properly track memory lifecycle states, resulting in references to memory regions that have been freed. When subsequent operations attempt to access or manipulate this freed memory, the application enters an undefined state leading to a crash.

Apple addressed this issue with improved memory management, implementing stricter tracking of object lifecycles and ensuring proper memory state validation before access operations.

Attack Vector

The attack vector for this vulnerability is network-based and requires user interaction. An attacker must entice a victim to visit a malicious website or load web content containing the exploit payload. The attack can be delivered through:

• Malicious websites specifically crafted to trigger the vulnerability
• Compromised legitimate websites injected with malicious content
• Phishing emails containing links to exploit pages
• Malicious advertisements (malvertising) served through ad networks
• Web content embedded in applications that use WebKit for rendering

The vulnerability affects the core Safari process, meaning successful exploitation causes the browser to crash, disrupting the user's browsing session.

Detection Methods for CVE-2025-30427

Indicators of Compromise

• Unexpected and repeated Safari browser crashes when visiting specific websites
• WebKit process crashes appearing in system logs (Console.app on macOS, Analytics data on iOS)
• Crash reports referencing WebKit memory operations or JavaScript engine components
• User reports of browser instability when accessing certain web content

Detection Strategies

• Monitor system crash logs for Safari or WebKit-related crash signatures
• Implement web content filtering to block known malicious domains targeting browser vulnerabilities
• Deploy endpoint detection solutions capable of identifying abnormal browser behavior patterns
• Review crash dumps for memory corruption signatures associated with use-after-free conditions

Monitoring Recommendations

• Enable crash reporting and analyze Safari crash patterns across managed devices
• Monitor network traffic for suspicious web content delivery patterns
• Implement browser isolation technologies for high-risk browsing activities
• Configure alerting for multiple Safari crashes occurring in short time periods

How to Mitigate CVE-2025-30427

Immediate Actions Required

• Update all Apple devices to the latest available operating system and Safari versions immediately
• Prioritize patching for devices regularly used for web browsing or accessing untrusted content
• Consider using alternative browsers temporarily if updates cannot be immediately applied
• Implement network-level web filtering to reduce exposure to malicious content

Patch Information

Apple has released patches addressing this vulnerability across all affected platforms. Organizations should update to the following versions or later:

• Safari: Update to version 18.4 or later
• iOS and iPadOS: Update to version 18.4 or later (or iPadOS 17.7.6 for devices on the 17.x branch)
• macOS Sequoia: Update to version 15.4 or later
• tvOS: Update to version 18.4 or later
• visionOS: Update to version 2.4 or later

For detailed patch information, refer to the official Apple security advisories:

• Apple Security Document #122371
• Apple Security Document #122372
• Apple Security Document #122373
• Apple Security Document #122377
• Apple Security Document #122378
• Apple Security Document #122379

Workarounds

• Enable web content blockers to reduce exposure to potentially malicious content
• Avoid visiting untrusted or suspicious websites until patches are applied
• Consider using managed browser configurations with enhanced security settings
• Implement network security controls such as DNS filtering and web proxies to block known malicious domains