CVE-2022-32907: Apple iPhone OS RCE Vulnerability

CVE-2022-32907 Overview

CVE-2022-32907 is a memory corruption vulnerability affecting multiple Apple operating systems including iOS, tvOS, and watchOS. The vulnerability exists in the AppleAVD component, specifically within the AppleAVDUserClient::decodeFrameFig function. This issue was addressed with improved checks. An app may be able to execute arbitrary code with kernel privileges, making this a significant local privilege escalation vulnerability.

Critical Impact

A malicious application can exploit this vulnerability to execute arbitrary code with kernel-level privileges, potentially achieving complete device compromise.

Affected Products

• Apple iPhone OS (iOS versions prior to iOS 16)
• Apple tvOS (versions prior to tvOS 16)
• Apple watchOS (versions prior to watchOS 9)

Discovery Timeline

• 2022-11-01 - CVE-2022-32907 published to NVD
• 2025-05-06 - Last updated in NVD database

Technical Details for CVE-2022-32907

Vulnerability Analysis

This vulnerability resides in the AppleAVD (Apple Video Decoder) kernel extension, which handles video decoding operations at the kernel level. The flaw is classified under CWE-269 (Improper Privilege Management), indicating that the vulnerability allows privilege escalation beyond what should be permitted. The attack requires local access with user interaction, meaning an attacker must convince a user to install a malicious application. Once executed, the application can leverage this memory corruption flaw to escalate privileges from user space to kernel space, granting complete control over the affected device.

Root Cause

The root cause stems from improper checks within the AppleAVD component's frame decoding functionality. The decodeFrameFig function in AppleAVDUserClient fails to properly validate input parameters or memory boundaries, leading to memory corruption conditions. Apple addressed this issue by implementing improved validation checks to ensure proper memory handling during video decoding operations.

Attack Vector

The attack vector is local, requiring an attacker to first deliver a malicious application to the target device. This could be accomplished through social engineering tactics such as convincing users to install applications from untrusted sources or by exploiting enterprise certificate distribution mechanisms. Once the malicious app is installed and executed with user interaction, it can trigger the vulnerability in the AppleAVD kernel extension.

The exploitation path involves the malicious application calling into the AppleAVD kernel extension through the AppleAVDUserClient interface. By supplying specially crafted parameters to the decodeFrameFig method, the attacker can corrupt kernel memory and gain arbitrary code execution with kernel privileges. Technical details of the memory corruption mechanism are documented in the Packet Storm Security Report.

Detection Methods for CVE-2022-32907

Indicators of Compromise

• Unusual processes or applications attempting to interact with the AppleAVD kernel extension
• System instability or unexpected crashes related to video decoding operations
• Applications exhibiting elevated privileges beyond their expected scope
• Suspicious kernel panics or logs referencing AppleAVD or video decoder components

Detection Strategies

• Monitor for applications attempting to make unusual IOKit calls to the AppleAVD service
• Implement application whitelisting to prevent unauthorized apps from executing
• Deploy mobile device management (MDM) solutions to detect unauthorized application installations
• Review device logs for anomalous AppleAVD-related kernel messages

Monitoring Recommendations

• Enable comprehensive system logging on iOS, tvOS, and watchOS devices where supported
• Use endpoint detection solutions capable of monitoring kernel extension interactions
• Monitor for applications requesting excessive permissions or exhibiting unexpected behavior
• Deploy network monitoring to detect potential command and control communications from compromised devices

How to Mitigate CVE-2022-32907

Immediate Actions Required

• Update all affected Apple devices to iOS 16, tvOS 16, or watchOS 9 or later immediately
• Review installed applications on all devices and remove any untrusted or unnecessary apps
• Enable automatic updates to ensure devices receive security patches promptly
• Restrict users from installing applications from sources outside the official App Store

Patch Information

Apple has released security updates addressing this vulnerability. Administrators should apply the following updates:

• iOS 16 - Available via Apple Security Update HT213446
• tvOS 16 - Available via Apple Security Update HT213487
• watchOS 9 - Available via Apple Security Update HT213486

These updates include improved checks to address the memory corruption vulnerability in the AppleAVD component.

Workarounds

• Restrict installation of applications to only those from the official Apple App Store
• Implement MDM policies to prevent sideloading of applications on enterprise devices
• Educate users about the risks of installing applications from untrusted sources
• Consider network segmentation to limit the impact of potentially compromised devices

# Verify iOS device software version
# On device: Settings > General > About > Software Version
# Ensure version is iOS 16.0 or later

# For enterprise MDM deployment, enforce minimum OS version policy
# Example MDM profile restriction (pseudo-configuration)
# <key>minOSVersion</key>
# <string>16.0</string>