CVE-2024-54534: Apple Safari Use-After-Free Vulnerability

CVE-2024-54534 Overview

CVE-2024-54534 is a memory corruption vulnerability affecting Apple Safari and multiple Apple operating systems. Processing maliciously crafted web content can trigger memory corruption, enabling remote attackers to compromise affected devices. The flaw is classified as an out-of-bounds write ([CWE-787]) and is exploitable over the network without authentication or user interaction beyond visiting a malicious page.

Apple addressed the issue with improved memory handling in Safari 18.2, iOS 18.2, iPadOS 18.2, iPadOS 17.7.6, macOS Sequoia 15.2, tvOS 18.2, visionOS 2.2, and watchOS 11.2.

Critical Impact
A remote attacker can trigger memory corruption by serving crafted web content to a vulnerable Safari or WebKit-based client, potentially leading to arbitrary code execution within the browser process.

Affected Products

Apple Safari (prior to 18.2)
Apple iOS and iPadOS (prior to 18.2 and 17.7.6)
Apple macOS Sequoia (prior to 15.2), tvOS (prior to 18.2), visionOS (prior to 2.2), and watchOS (prior to 11.2)

Discovery Timeline

2024-12-12 - CVE-2024-54534 published to the National Vulnerability Database (NVD)
2026-04-02 - Last updated in NVD database

Technical Details for CVE-2024-54534

Vulnerability Analysis

The vulnerability resides in Apple's WebKit browser engine, which powers Safari and renders web content across Apple's operating systems. Apple's advisory states the issue was addressed with improved memory handling, indicating the root cause involved unsafe memory operations during processing of crafted web content.

The weakness is categorized as an out-of-bounds write ([CWE-787]). Out-of-bounds writes occur when code writes data past the end or before the beginning of an allocated buffer. In a JavaScript engine or DOM rendering pipeline, such writes can corrupt adjacent objects, function pointers, or heap metadata.

Attackers leverage this primitive to craft heap layouts that turn memory corruption into reliable arbitrary code execution within the renderer process. From there, additional sandbox escape vulnerabilities are typically chained to achieve full device compromise.

Root Cause

The underlying defect is improper validation of buffer boundaries during processing of maliciously crafted web content. Insufficient bounds checking in WebKit's memory handling code allows attacker-controlled inputs to write outside intended memory regions, corrupting internal data structures used by the engine.

Attack Vector

Exploitation requires a victim to load attacker-controlled web content in a vulnerable WebKit-based application. The attack vector is network-based and requires no privileges. Delivery channels include malicious websites, compromised legitimate sites, malvertising, embedded WebViews in third-party applications, and links delivered through email or messaging applications.

No verified proof-of-concept exploit is publicly available for this CVE. Technical details for affected components are documented in the Apple Support Document 121837 and related advisories.

Detection Methods for CVE-2024-54534

Indicators of Compromise

Safari, Apple WebKit, or com.apple.WebKit.WebContent process crashes correlated with visits to untrusted URLs
Unexpected child processes spawned by Safari or WebKit-based applications shortly after browsing activity
Outbound network connections from browser processes to uncategorized or newly registered domains following page loads

Detection Strategies

Inventory endpoints running Safari, iOS, iPadOS, macOS, tvOS, visionOS, and watchOS versions below the fixed releases listed in Apple's advisories
Monitor for repeated renderer crashes in WebKit and Safari processes, which can indicate failed or successful exploitation attempts
Correlate browser process anomalies with web proxy logs to identify malicious URLs serving crafted content

Monitoring Recommendations

Forward endpoint telemetry, browser crash logs, and DNS query data to a centralized analytics platform for correlation
Track installed Safari and OS build versions across the fleet and alert on devices remaining below patched versions
Enable threat intelligence feeds covering WebKit exploitation campaigns and known malicious infrastructure

How to Mitigate CVE-2024-54534

Immediate Actions Required

Update affected devices to Safari 18.2, iOS 18.2, iPadOS 18.2 or 17.7.6, macOS Sequoia 15.2, tvOS 18.2, visionOS 2.2, and watchOS 11.2 or later
Prioritize patching of internet-facing user devices and high-value executive endpoints
Restrict browsing to trusted sites on unpatched devices until updates are applied

Patch Information

Apple released patches across its product line on December 11, 2024. Refer to the official Apple advisories: Apple Support Document 121837, 121839, 121843, 121844, 121845, and 121846. NetApp also published downstream guidance in NTAP-20250418-0002.

Workarounds

Block access to untrusted websites at the network perimeter using web filtering or DNS-based security controls
Disable JavaScript in Safari for high-risk user groups until patches are deployed, accepting functional trade-offs
Use Mobile Device Management (MDM) policies to enforce minimum OS versions and prevent enrollment of out-of-date devices

bash

# Verify Safari version on macOS
defaults read /Applications/Safari.app/Contents/Info.plist CFBundleShortVersionString

# Check macOS build version
sw_vers

# Trigger software update check
sudo softwareupdate --list
sudo softwareupdate --install --all --restart