CVE-2024-32913: Google Android RCE Vulnerability

CVE-2024-32913 Overview

CVE-2024-32913 is a critical integer overflow vulnerability in the wl_notify_rx_mgmt_frame function within wl_cfg80211.c, a core component of Android's WiFi driver subsystem. This vulnerability enables an attacker to trigger an out-of-bounds write condition, potentially leading to remote code execution on affected devices without requiring any user interaction or additional execution privileges.

Critical Impact

This vulnerability allows unauthenticated remote attackers to execute arbitrary code on Android devices via crafted WiFi management frames, potentially gaining complete control over the affected device without any user interaction.

Affected Products

• Google Android (all versions prior to June 2024 security patch)
• Google Pixel devices running unpatched firmware
• Android devices using the affected WiFi driver component

Discovery Timeline

• June 1, 2024 - Android Security Bulletin published addressing this vulnerability
• June 13, 2024 - CVE-2024-32913 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-32913

Vulnerability Analysis

The vulnerability resides in the WiFi configuration management layer of Android, specifically within the wl_notify_rx_mgmt_frame function in wl_cfg80211.c. This function is responsible for processing incoming WiFi management frames, which are used for device discovery, authentication, and network management operations.

The root cause is an integer overflow condition (CWE-190) that occurs during the processing of management frame data. When specially crafted management frames are received, the integer overflow leads to an incorrect buffer size calculation, subsequently causing an out-of-bounds write operation. This memory corruption primitive can be leveraged by an attacker to achieve remote code execution.

The network-based attack vector means that an attacker within WiFi range of a vulnerable device can exploit this vulnerability without any prerequisites—no authentication, no user interaction, and no special privileges are required on the target device.

Root Cause

The vulnerability stems from insufficient validation of size parameters in the wl_notify_rx_mgmt_frame function. When processing WiFi management frames, the code performs arithmetic operations on length values that can result in an integer overflow. This overflow causes a smaller-than-expected buffer to be allocated or an incorrect bounds check to pass, allowing subsequent write operations to exceed the intended memory boundaries.

Integer overflow vulnerabilities in low-level network drivers are particularly dangerous because they operate in a privileged context and process untrusted network data directly. The WiFi subsystem processes management frames at a fundamental level, making exploitation reliable and difficult to detect.

Attack Vector

The attack can be executed remotely over a WiFi network by an attacker within wireless range of the target device. The exploitation flow involves:

1. The attacker crafts malicious WiFi management frames with specially constructed length fields designed to trigger the integer overflow condition
2. These frames are transmitted over the air to the target device
3. The vulnerable wl_notify_rx_mgmt_frame function processes the malicious frame
4. The integer overflow causes an incorrect buffer size calculation
5. The subsequent out-of-bounds write corrupts memory, enabling code execution
6. The attacker gains code execution with kernel-level privileges on the device

The vulnerability mechanism involves the handling of frame length parameters in the WiFi management frame processing code. When a malformed frame arrives with length values crafted to cause an integer overflow during size calculations, the resulting value wraps around to a smaller number. This leads to memory corruption when the actual frame data exceeds the incorrectly calculated buffer size. For detailed technical analysis, refer to the Android Security Bulletin June 2024.

Detection Methods for CVE-2024-32913

Indicators of Compromise

• Unexpected device reboots or system crashes when connected to WiFi networks
• Anomalous WiFi management frame traffic patterns in wireless network monitoring
• Unusual kernel log entries related to WiFi driver memory errors
• Signs of unauthorized access or data exfiltration following WiFi connectivity

Detection Strategies

• Deploy wireless intrusion detection systems (WIDS) to monitor for malformed WiFi management frames
• Implement kernel-level monitoring for memory corruption indicators in the WiFi driver subsystem
• Monitor Android system logs for crashes or anomalies in wl_cfg80211 related components
• Use mobile device management (MDM) solutions to verify patch compliance across device fleets

Monitoring Recommendations

• Enable verbose logging for WiFi driver components on security-sensitive devices
• Implement network-level monitoring for unusual 802.11 management frame patterns
• Configure endpoint detection and response (EDR) solutions to alert on WiFi driver anomalies
• Regularly audit device firmware versions against the June 2024 security baseline

How to Mitigate CVE-2024-32913

Immediate Actions Required

• Apply the June 2024 Android security patch immediately on all affected devices
• For Google Pixel devices, update to the latest available firmware version
• Consider disabling WiFi on high-value devices until patches can be applied
• Implement network segmentation to limit exposure of vulnerable devices

Patch Information

Google has addressed this vulnerability in the Android Security Bulletin June 2024. The patch resolves the integer overflow condition by implementing proper bounds checking and validation of frame length parameters before memory allocation and write operations occur.

Organizations should prioritize deployment of this security update given the critical nature of the vulnerability and the potential for remote exploitation without user interaction. The patch is available through standard Android update channels for Pixel devices and through device manufacturers for other Android devices.

Workarounds

• Disable WiFi functionality on devices that cannot be immediately patched
• Use wired or cellular connectivity as an alternative to WiFi on vulnerable devices
• Implement strict physical security controls to limit attacker proximity to vulnerable devices
• Deploy network access control to restrict untrusted WiFi access points

# Android device security verification
# Check current security patch level on Android device via ADB
adb shell getprop ro.build.version.security_patch
# Expected output should be 2024-06-01 or later

# Verify WiFi driver module information
adb shell lsmod | grep wlan