CVE-2023-40100
📋 TL;DR
This vulnerability allows local privilege escalation on Android devices due to memory corruption in DNS64 configuration handling. It affects Android systems with the vulnerable DNS resolver component, potentially enabling attackers to gain elevated privileges without user interaction.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
Android by Google
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains full system control (root access) on the device, compromising all data and functionality.
Likely Case
Local privilege escalation leading to unauthorized access to sensitive system resources or data.
If Mitigated
Limited impact if patched; otherwise, risk persists for unpatched devices.
🎯 Exploit Status
Exploitation requires local access but no user interaction; memory corruption techniques may be needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Android security patch level November 2023 or later
Vendor Advisory: https://source.android.com/security/bulletin/2023-11-01
Restart Required: Yes
Instructions:
1. Check for system updates in device settings. 2. Apply the November 2023 Android security patch. 3. Reboot the device after installation.
🔧 Temporary Workarounds
Disable DNS64 if not needed
androidTurn off DNS64 configuration to reduce attack surface, but this may affect IPv6 connectivity.
🧯 If You Can't Patch
- Restrict app installations to trusted sources only to reduce risk of malicious local exploitation.
- Monitor device logs for unusual activity related to DNS resolver processes.
🔍 How to Verify
Check if Vulnerable:
Check the Android security patch level in Settings > About phone > Android version; if before November 2023, it may be vulnerable.Check Version:
Use 'adb shell getprop ro.build.version.security_patch' to check patch level via ADB.Verify Fix Applied:
Confirm the security patch level is November 2023 or later after applying updates.📡 Detection & Monitoring
Log Indicators:
- Unusual crashes or errors in DNS resolver logs (e.g., logcat entries related to Dns64Configuration)
Network Indicators:
- Abnormal DNS query patterns, though exploitation is local
SIEM Query:
Search for log events containing 'Dns64Configuration' or 'discovery_thread' errors on Android devices.🔗 References
- https://android.googlesource.com/platform/packages/modules/DnsResolver/+/8e1561fb603fdaec15798372f865fb1750537f4f
- https://source.android.com/security/bulletin/2023-11-01
- https://android.googlesource.com/platform/packages/modules/DnsResolver/+/8e1561fb603fdaec15798372f865fb1750537f4f
- https://source.android.com/security/bulletin/2023-11-01
