CVE-2022-42837: Apple iPadOS RCE Vulnerability

CVE-2022-42837 Overview

CVE-2022-42837 is an input validation flaw in Apple's URL parsing logic across multiple operating systems. A remote attacker can supply a crafted URL that triggers unexpected application termination or arbitrary code execution. The issue affects iOS, iPadOS, macOS Ventura, and watchOS. Apple addressed the flaw with improved input validation in iOS 16.2, iPadOS 16.2, macOS Ventura 13.1, iOS 15.7.2, iPadOS 15.7.2, and watchOS 9.2. The vulnerability is classified under [CWE-20] (Improper Input Validation) and carries a network attack vector requiring no privileges or user interaction.

Critical Impact

A remote attacker can trigger arbitrary code execution or app termination by delivering a malicious URL to an affected Apple device.

Affected Products

• Apple iOS and iPadOS (versions prior to 16.2 and 15.7.2)
• Apple macOS Ventura (versions prior to 13.1)
• Apple watchOS (versions prior to 9.2)

Discovery Timeline

• 2022-12-15 - CVE-2022-42837 published to NVD
• 2025-04-21 - Last updated in NVD database

Technical Details for CVE-2022-42837

Vulnerability Analysis

The vulnerability resides in how Apple operating systems parse URLs. Insufficient validation of URL components allows specially crafted input to corrupt parser state. Once the parser mishandles the input, downstream consumers of the parsed URL can be coerced into unsafe operations. The result is either an unexpected application crash or, in worse cases, arbitrary code execution within the context of the calling application.

The vulnerability is reachable remotely. An attacker only needs to deliver a malicious URL through any vector that hands the string to the affected parser, such as a webpage, message, or shared link. No authentication is required and the user does not need to interact with a prompt for exploitation to succeed.

Root Cause

The root cause is improper input validation in the URL parsing routines [CWE-20]. The parser accepts malformed or boundary-condition input without verifying structural assumptions, leading to memory or logic state inconsistencies. Apple's advisories describe the fix as improved input validation, which indicates the original code path did not enforce sufficient constraints on incoming URL data.

Attack Vector

Exploitation occurs over the network. An attacker hosts or transmits a crafted URL and induces the target system to parse it. Because the parser is shared by multiple platform components, the attack surface includes any application that consumes URLs through system APIs. Successful exploitation can lead to full compromise of the affected application's confidentiality, integrity, and availability.

No verified public proof-of-concept code is available. The vulnerability mechanism is described in prose per Apple's advisories. For technical details, see Apple Support Article HT213535 and the Apple Security Update HT213530.

Detection Methods for CVE-2022-42837

Indicators of Compromise

• Unexpected crashes or hangs of applications that handle URLs, recorded in /Library/Logs/DiagnosticReports/ on macOS or device crash logs on iOS.
• Anomalous outbound connections following processing of inbound links from email, messaging apps, or web browsers.
• Presence of OS or browser versions below the fixed releases on managed Apple devices.

Detection Strategies

• Inventory Apple endpoints and flag systems running iOS or iPadOS below 15.7.2 and 16.2, macOS Ventura below 13.1, or watchOS below 9.2.
• Correlate crash telemetry from URL-handling processes with inbound link delivery events from email and messaging gateways.
• Inspect web and email gateway logs for URLs containing malformed schemes, unusual encodings, or excessive structural complexity.

Monitoring Recommendations

• Forward Apple device crash reports and unified logs to a centralized log platform for retrospective analysis.
• Monitor mobile device management (MDM) compliance dashboards for OS version drift on enrolled Apple endpoints.
• Alert on repeated application restarts of browsers, messaging clients, or mail clients on the same device.

How to Mitigate CVE-2022-42837

Immediate Actions Required

• Update all affected Apple devices to iOS 16.2, iPadOS 16.2, macOS Ventura 13.1, iOS 15.7.2, iPadOS 15.7.2, or watchOS 9.2 or later.
• Use MDM tooling to enforce minimum OS versions and quarantine non-compliant devices from sensitive resources.
• Educate users to avoid opening untrusted links from email, SMS, or messaging applications until patches are applied.

Patch Information

Apple released fixes in iOS 16.2 and iPadOS 16.2, macOS Ventura 13.1, iOS 15.7.2 and iPadOS 15.7.2, and watchOS 9.2. Refer to Apple Security Update HT213530, Apple Security Update HT213531, Apple Security Update HT213532, and Apple Security Update HT213536 for the full list of addressed issues and update instructions.

Workarounds

• No vendor-supplied workaround exists; applying the patches is the authoritative remediation.
• Restrict delivery of untrusted URLs through email and messaging filters until devices are confirmed updated.
• Disable link previews in messaging clients on unpatched devices to reduce automatic parser invocation.

# Verify macOS version meets the patched baseline
sw_vers -productVersion
# Expected: 13.1 or later for Ventura systems

# On iOS/iPadOS, confirm via Settings > General > About > Software Version
# Required: 15.7.2 / 16.2 or later