CVE-2023-21046
📋 TL;DR
This vulnerability allows local information disclosure on Android devices through an out-of-bounds read in the ConvertToHalMetadata function. Attackers with system execution privileges can exploit this without user interaction. Only Android devices with specific kernel versions are affected.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Local attacker with system privileges could read sensitive kernel memory, potentially exposing cryptographic keys, passwords, or other protected data.
Likely Case
Limited information disclosure to malicious apps with elevated privileges, potentially exposing some system metadata or configuration data.
If Mitigated
No impact if proper privilege separation is enforced and apps are prevented from obtaining system execution privileges.
🎯 Exploit Status
Requires system execution privileges and knowledge of the vulnerability. No public exploit code known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android security patch level March 2023 or later
Vendor Advisory: https://source.android.com/security/bulletin/pixel/2023-03-01
Restart Required: Yes
Instructions:
1. Check for Android system updates in Settings > System > System update. 2. Install the March 2023 security patch or later. 3. Reboot device after installation.
🔧 Temporary Workarounds
Restrict system privileges
androidLimit which apps can obtain system execution privileges through Android's permission system
adb shell pm revoke <package_name> android.permission.INTERACT_ACROSS_USERS_FULL
🧯 If You Can't Patch
- Implement strict app vetting and only install apps from trusted sources
- Use Android's work profile or containerization to isolate potentially malicious apps
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Android version > Security patch level. If before March 2023, device is vulnerable.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify security patch level shows March 2023 or later date after update.📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing memory access violations or segmentation faults in aidl_utils.cc
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="android_kernel" AND ("aidl_utils" OR "ConvertToHalMetadata") AND ("segfault" OR "oob" OR "out of bounds")