CVE-2023-21073
📋 TL;DR
This CVE describes a buffer overflow vulnerability in the Android kernel's dhd_rtt.c file that allows local privilege escalation. Attackers with system execution privileges can exploit this without user interaction to gain elevated access. The vulnerability affects Android devices with specific kernel versions.
💻 Affected Systems
- Android
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code with kernel privileges, potentially installing persistent malware or accessing all device data.
Likely Case
Local privilege escalation from a compromised app or process to kernel-level access, enabling further system manipulation.
If Mitigated
Limited impact if proper kernel hardening, SELinux policies, and privilege separation are implemented.
🎯 Exploit Status
Exploitation requires existing system execution privileges. No public exploit code is known, but the vulnerability is well-documented in Android security bulletins.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2023 Android security patch level 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 March 2023 or later security patch. 3. Reboot device after installation. 4. Verify patch level in Settings > About phone > Android version.
🔧 Temporary Workarounds
Restrict app permissions
androidLimit which apps have system-level permissions to reduce attack surface
Disable unnecessary system services
androidReduce exposure by disabling unused RTT (Round Trip Time) or location services if not needed
🧯 If You Can't Patch
- Implement strict app vetting and only install apps from trusted sources
- Use mobile device management (MDM) solutions to enforce security policies and monitor for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Android version. If patch level is 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 in Settings > About phone > Android version.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- SELinux denials related to dhd_rtt or RTT operations
- Unexpected privilege escalation attempts
SIEM Query:
source="android_kernel" AND ("dhd_rtt" OR "CVE-2023-21073" OR "A-257290396")