CVE-2023-21052
📋 TL;DR
This vulnerability allows local privilege escalation on Android devices through an out-of-bounds write in the RIL (Radio Interface Layer) component. Attackers with system execution privileges can exploit this to gain elevated access without user interaction. Affected devices include those running vulnerable Android kernel versions.
💻 Affected Systems
- Android devices
📦 What is this software?
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to execute arbitrary code with kernel privileges, potentially installing persistent malware or accessing sensitive system data.
Likely Case
Local privilege escalation enabling attackers to bypass security restrictions and gain elevated system access on compromised devices.
If Mitigated
Limited impact if devices are fully patched and have proper security controls like SELinux enforcement and minimal privilege applications.
🎯 Exploit Status
Requires system execution privileges for initial access. No user interaction needed once initial access is obtained.
🛠️ 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 system updates in Settings > System > System update. 2. Install March 2023 Android security patch. 3. Reboot device after installation.
🔧 Temporary Workarounds
Restrict app permissions
androidLimit system permissions for applications to reduce attack surface
Enable SELinux enforcing mode
androidEnsure SELinux is in enforcing mode to limit privilege escalation impact
getenforce
🧯 If You Can't Patch
- Isolate vulnerable devices from sensitive networks and data
- Implement application allowlisting to prevent unauthorized apps from obtaining system privileges
🔍 How to Verify
Check if Vulnerable:
Check Android security patch level in Settings > About phone > Android version. If patch level is earlier than 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 RIL services
- Unexpected privilege escalation attempts
Network Indicators:
- Unusual RIL communication patterns
SIEM Query:
source="android_kernel" AND (event="panic" OR event="oops") AND process="ril-daemon"