CVE-2024-31339: Google Android Use-After-Free Flaw

CVE-2024-31339 Overview

CVE-2024-31339 is a use after free vulnerability affecting multiple functions within StatsService.cpp in Google Android's StatsD module. The vulnerability results from improper memory management that can lead to memory corruption, enabling a local attacker to escalate privileges on the affected device without requiring additional execution privileges or user interaction.

Critical Impact

This vulnerability allows local privilege escalation through memory corruption with no user interaction required, potentially enabling attackers to gain elevated system access on vulnerable Android devices.

Affected Products

• Google Android 12.0
• Google Android 12.1
• Google Android 13.0
• Google Android 14.0

Discovery Timeline

• July 9, 2024 - CVE-2024-31339 published to NVD
• December 17, 2024 - Last updated in NVD database

Technical Details for CVE-2024-31339

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption class vulnerability that occurs when a program continues to reference memory after it has been freed. In the context of StatsService.cpp, the vulnerability manifests in multiple functions within the StatsD module, which is responsible for collecting and aggregating system metrics in Android.

Use after free vulnerabilities occur when memory is deallocated but pointers to that memory are not properly nullified or cleared. Subsequent operations that reference these dangling pointers can lead to unpredictable behavior, memory corruption, or code execution. The local attack vector means an attacker would need initial access to the device, but once exploited, they can achieve privilege escalation without any user interaction or additional privileges.

Root Cause

The root cause of CVE-2024-31339 lies in improper memory lifecycle management within the StatsService.cpp component. The vulnerability occurs when memory objects are freed but references to those objects persist in code paths that continue to access the deallocated memory. This creates a window where the freed memory can be reallocated for other purposes, and subsequent access through the stale pointer corrupts the new data or allows execution of attacker-controlled code.

Attack Vector

The attack vector for this vulnerability is local, meaning an attacker must have some level of access to the target Android device. The exploitation scenario involves:

1. A malicious application or process running on the device triggers the vulnerable code path in StatsService
2. The attacker manipulates memory allocation patterns to control what data occupies the freed memory region
3. When the dangling pointer is dereferenced, the attacker can corrupt memory structures or redirect execution flow
4. Successful exploitation results in privilege escalation, allowing the attacker to execute code with elevated permissions

The vulnerability is particularly concerning because it requires no user interaction and no additional execution privileges to exploit, lowering the barrier for successful attacks.

Detection Methods for CVE-2024-31339

Indicators of Compromise

• Unexpected crashes or restarts of the statsd service on Android devices
• Anomalous memory allocation patterns in system services
• Unauthorized privilege escalation events logged in system audit records
• Unexpected process spawning with elevated privileges

Detection Strategies

• Monitor Android system logs for statsd service crashes or abnormal behavior patterns
• Implement memory corruption detection tools that can identify use after free conditions
• Deploy mobile device management (MDM) solutions that can detect exploitation attempts
• Utilize SentinelOne's Singularity Mobile to identify malicious applications attempting to exploit system vulnerabilities

Monitoring Recommendations

• Enable enhanced logging for Android system services to capture anomalous StatsService behavior
• Implement runtime application self-protection (RASP) on critical Android deployments
• Regularly audit installed applications for potentially malicious behavior targeting system services
• Monitor for applications requesting unusual permissions or exhibiting privilege escalation behavior

How to Mitigate CVE-2024-31339

Immediate Actions Required

• Apply the July 2024 Android Security Bulletin patches immediately to all affected devices
• Prioritize patching for devices running Android 12.0, 12.1, 13.0, and 14.0
• Review installed applications and remove any untrusted or unnecessary apps that could exploit this vulnerability
• Enable automatic security updates on all Android devices where possible

Patch Information

Google has released security patches addressing this vulnerability as part of the Android Security Bulletin July 2024. The specific fix can be reviewed in the Android Source Code Change with commit hash 795a0da721992432cae20fc9be21bcbce318bf5a. Organizations should coordinate with device manufacturers and carriers to ensure timely deployment of security patches.

Workarounds

• Limit application installations to trusted sources (Google Play Store) to reduce the risk of malicious applications
• Implement mobile device management (MDM) policies to restrict application permissions and enforce security baselines
• Consider device isolation for critical enterprise deployments until patches can be applied
• Monitor devices for suspicious activity using endpoint detection and response solutions

# Verify Android security patch level on device
adb shell getprop ro.build.version.security_patch
# Expected output should be 2024-07-01 or later for patched devices