CVE-2023-21048
📋 TL;DR
This CVE describes an out-of-bounds read vulnerability in the Android kernel's nan.cpp component. It could allow local information disclosure to attackers with system execution privileges, requiring no user interaction. Affected systems include Android devices with vulnerable kernel versions.
💻 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 from kernel memory to a malicious app with elevated privileges.
If Mitigated
No impact if proper privilege separation and kernel hardening are implemented.
🎯 Exploit Status
Requires system privileges and knowledge of kernel memory layout. No public exploit code identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2023 Android security patch level
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. Apply March 2023 or later security patch. 3. Reboot device after update completes.
🔧 Temporary Workarounds
Restrict system privileges
androidLimit apps with system execution privileges using SELinux policies and app permissions.
adb shell setenforce 1
adb shell getenforce
🧯 If You Can't Patch
- Implement strict app vetting and permission controls to prevent malicious apps from obtaining system privileges.
- Use Android Enterprise or MDM solutions to enforce security policies and isolate vulnerable devices.
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Android version. 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 after update.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- SELinux denials related to nan.cpp
- Abnormal memory access patterns in kernel logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="android_kernel" AND ("nan.cpp" OR "out of bounds read")