CVE-2022-22624: Apple Safari Use-After-Free Vulnerability

CVE-2022-22624 Overview

CVE-2022-22624 is a use after free vulnerability affecting Apple's WebKit browser engine, which powers Safari and web content across Apple's ecosystem of devices. This memory corruption flaw occurs when processing maliciously crafted web content, potentially allowing attackers to execute arbitrary code on affected systems. The vulnerability was addressed by Apple with improved memory management in their March 2022 security updates.

Critical Impact

Processing maliciously crafted web content may lead to arbitrary code execution, potentially allowing attackers to gain complete control over affected devices including iPhones, iPads, Macs, and Apple TVs.

Affected Products

• Apple Safari versions prior to 15.4
• Apple iOS versions prior to 15.4
• Apple iPadOS versions prior to 15.4
• Apple macOS Monterey versions prior to 12.3
• Apple tvOS versions prior to 15.4

Discovery Timeline

• September 23, 2022 - CVE-2022-22624 published to NVD
• May 22, 2025 - Last updated in NVD database

Technical Details for CVE-2022-22624

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a critical memory corruption vulnerability class that occurs when a program continues to use a pointer after the memory it references has been freed. In the context of WebKit, this flaw manifests during the processing of web content, where specific sequences of operations can trigger a condition where freed memory is subsequently accessed.

Use after free vulnerabilities in browser engines are particularly dangerous because they can be exploited remotely through malicious web pages. An attacker only needs to convince a victim to visit a specially crafted website to trigger the vulnerability. Given that WebKit is the rendering engine for Safari and all iOS browsers (due to Apple's App Store policies requiring the use of WebKit), the attack surface is substantial across the Apple ecosystem.

Root Cause

The root cause of CVE-2022-22624 lies in improper memory management within WebKit's web content processing routines. When certain objects are deallocated during the rendering or JavaScript execution pipeline, references to those objects may not be properly invalidated. Subsequent operations that attempt to access these stale references encounter freed memory regions, leading to undefined behavior that attackers can weaponize.

Apple addressed this issue by implementing improved memory management, which likely includes proper nullification of pointers after deallocation, enhanced reference counting mechanisms, or modifications to the object lifecycle to prevent premature deallocation while references remain active.

Attack Vector

The attack vector for this vulnerability is network-based and requires user interaction. An attacker must craft malicious web content that triggers the use after free condition when rendered by WebKit. The typical attack scenario involves:

1. The attacker creates a malicious webpage containing specially crafted HTML, CSS, or JavaScript designed to manipulate WebKit's memory allocation patterns
2. The victim is lured to visit the malicious page through phishing, malvertising, or compromised legitimate websites
3. Upon loading the content, WebKit's rendering engine processes the malicious payload
4. The exploitation causes a memory object to be freed while references to it still exist
5. Subsequent access to the freed memory allows the attacker to control program execution flow, potentially achieving arbitrary code execution

The vulnerability can be exploited remotely across the network without requiring any privileges on the target system, though user interaction (visiting the malicious page) is necessary to initiate the attack.

Detection Methods for CVE-2022-22624

Indicators of Compromise

• Unexpected Safari or WebKit crashes accompanied by memory access violation errors
• Unusual network connections initiated by browser processes following visits to unfamiliar websites
• Process spawn anomalies where Safari or WebKit-based applications launch child processes with unexpected command-line arguments
• Memory allocation patterns showing abnormal heap behavior in WebKit processes

Detection Strategies

• Monitor for WebKit process crashes with memory corruption signatures in system diagnostic logs
• Implement web content filtering to block known malicious domains and newly registered suspicious sites
• Deploy endpoint detection solutions capable of identifying exploitation attempts through behavioral analysis of browser processes
• Analyze network traffic for connections to known threat infrastructure following web browsing activity

Monitoring Recommendations

• Enable crash reporting on Apple devices to capture diagnostic information when WebKit encounters memory corruption issues
• Review Console.app logs for WebKit-related error messages indicating memory management problems
• Monitor system resource utilization for anomalous patterns in Safari or WebKit processes that could indicate exploitation attempts
• Implement centralized logging for enterprise-managed Apple devices to correlate potential exploitation events across the fleet

How to Mitigate CVE-2022-22624

Immediate Actions Required

• Update all Apple devices to the patched versions: macOS Monterey 12.3, iOS 15.4, iPadOS 15.4, tvOS 15.4, and Safari 15.4 or later
• Enable automatic software updates on all Apple devices to ensure timely deployment of security patches
• Educate users about the risks of visiting untrusted websites and clicking on suspicious links
• Consider deploying web filtering solutions to reduce exposure to potentially malicious web content

Patch Information

Apple has released security updates addressing this vulnerability across all affected platforms. Organizations and users should apply the following updates immediately:

• macOS Monterey 12.3 - Details available in Apple Security Advisory HT213183
• iOS 15.4 and iPadOS 15.4 - Details available in Apple Security Advisory HT213182
• tvOS 15.4 - Details available in Apple Security Advisory HT213186
• Safari 15.4 - Details available in Apple Security Advisory HT213187

Workarounds

• If immediate patching is not possible, limit web browsing to trusted sites only on unpatched devices
• Consider using browser extensions or security software that can block potentially malicious JavaScript execution
• Disable JavaScript in Safari settings as a temporary measure (Settings > Safari > Advanced > JavaScript), though this may significantly impact web functionality
• Restrict network access for unpatched devices where feasible to minimize exposure to malicious web content

# Check current Safari version on macOS
/Applications/Safari.app/Contents/MacOS/Safari --version

# Check macOS version to verify patch status
sw_vers -productVersion
# Expected output for patched systems: 12.3 or higher for Monterey

# Enable automatic updates on macOS via command line
sudo softwareupdate --schedule on