CVE-2024-31328: Google Android Privilege Escalation Flaw

CVE-2024-31328 Overview

CVE-2024-31328 is a local privilege escalation vulnerability affecting Google Android's BroadcastController.java component. The vulnerability exists in the broadcastIntentLockedTraced function, where a logic error allows malicious actors to launch arbitrary activities from the background on the paired companion phone. This flaw enables local escalation of privilege without requiring any additional execution privileges or user interaction.

Critical Impact

Attackers can exploit this logic error to launch arbitrary activities in the background on paired companion devices, leading to local privilege escalation without user interaction.

Affected Products

• Google Android 14.0
• Google Android 16.0

Discovery Timeline

• 2026-03-02 - CVE-2024-31328 published to NVD
• 2026-03-03 - Last updated in NVD database

Technical Details for CVE-2024-31328

Vulnerability Analysis

This vulnerability is classified under CWE-693 (Protection Mechanism Failure), indicating a fundamental breakdown in the security controls designed to prevent unauthorized activity launching. The flaw resides within Android's broadcast intent handling mechanism, specifically in the broadcastIntentLockedTraced method of BroadcastController.java.

The logic error allows applications to circumvent background activity launch restrictions when communicating between a wearable device and its paired companion phone. Under normal circumstances, Android enforces strict limitations on background activity launches to prevent apps from disrupting user experience or performing malicious operations covertly. However, this vulnerability bypasses those protections entirely.

The attack requires adjacent network access, meaning the attacker must be within proximity to exploit the Wear OS companion device pairing mechanism. Despite this limitation, the vulnerability requires no privileges and no user interaction, making it highly exploitable once an attacker gains adjacent network access.

Root Cause

The root cause is a logic error in the broadcastIntentLockedTraced method within BroadcastController.java. The code fails to properly validate or restrict broadcast intents that originate from paired companion devices, allowing them to bypass the standard background activity launch restrictions. This protection mechanism failure enables unauthorized activity launches that should normally be blocked by Android's security framework.

Attack Vector

The vulnerability is exploited via adjacent network access, targeting the communication channel between Android Wear OS devices and their paired companion phones. An attacker positioned on the same local network or within Bluetooth range can craft malicious broadcast intents that trigger arbitrary activity launches on the victim's companion phone.

The attack flow involves:

1. Attacker gains adjacent network access to target Wear OS device pairing
2. Malicious broadcast intent is crafted to exploit the logic error in broadcastIntentLockedTraced
3. The vulnerable method fails to apply proper restrictions
4. Arbitrary activities are launched on the paired companion phone
5. Privilege escalation is achieved without user awareness

Detection Methods for CVE-2024-31328

Indicators of Compromise

• Unexpected background activity launches on Android devices paired with Wear OS devices
• Anomalous broadcast intent patterns in system logs related to companion device communication
• Unauthorized applications gaining elevated privileges without user interaction
• Suspicious activity in BroadcastController logs showing bypassed restrictions

Detection Strategies

• Monitor Android system logs for unusual broadcastIntentLockedTraced invocations from paired devices
• Implement anomaly detection for background activity launches that bypass standard restrictions
• Deploy mobile threat defense solutions capable of detecting privilege escalation attempts
• Analyze broadcast intent traffic between Wear OS and companion devices for malicious patterns

Monitoring Recommendations

• Enable verbose logging for broadcast intent processing on Android devices
• Monitor for applications unexpectedly gaining background activity launch capabilities
• Track companion device pairing events and subsequent broadcast intent activity
• Implement behavioral analysis for detecting privilege escalation patterns

How to Mitigate CVE-2024-31328

Immediate Actions Required

• Update affected Android devices to the latest security patch level (March 2026 or later)
• Review paired Wear OS devices and remove any untrusted connections
• Enable additional monitoring for broadcast intent activity on critical devices
• Consider temporarily disabling Wear OS companion features on high-security devices until patched

Patch Information

Google has addressed this vulnerability in the Android Wear Security Bulletin - March 2026. Organizations should ensure all Android devices running versions 14.0 and 16.0 are updated to include the security patches dated 2026-03-01 or later.

The patch corrects the logic error in broadcastIntentLockedTraced to properly enforce background activity launch restrictions for broadcast intents originating from companion devices.

Workarounds

• Limit Wear OS device pairing to trusted networks only
• Disable Wear OS companion features on devices where they are not required
• Implement network segmentation to isolate wearable device traffic
• Deploy mobile device management (MDM) solutions to enforce security policies and restrict unauthorized pairing

# Verify Android security patch level
adb shell getprop ro.build.version.security_patch
# Expected output should be 2026-03-01 or later