CVE-2023-42738
📋 TL;DR
CVE-2023-42738 is a missing permission check vulnerability in the telocom service that allows local attackers to escalate privileges without requiring additional execution privileges. This affects systems running vulnerable versions of Unisoc/Spreadtrum software. The vulnerability enables attackers to gain elevated access on compromised devices.
💻 Affected Systems
- Unisoc/Spreadtrum telocom service
📦 What is this software?
Android by Google
Android by Google
Android by Google
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where an attacker gains root/admin privileges, potentially installing persistent malware, accessing sensitive data, or disabling security controls.
Likely Case
Local privilege escalation allowing attackers to bypass application sandboxes, access protected system resources, or modify system configurations.
If Mitigated
Limited impact if proper application sandboxing, SELinux/AppArmor policies, and least privilege principles are enforced.
🎯 Exploit Status
Exploitation requires local access to the device. No public exploit code was found in the provided references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in references; check vendor advisory for specific patched versions
Vendor Advisory: https://www.unisoc.com/en_us/secy/announcementDetail/1731138365803266049
Restart Required: Yes
Instructions:
1. Check the Unisoc security advisory for affected versions. 2. Apply vendor-provided firmware/security updates. 3. Reboot the device after patching. 4. Verify the patch is applied successfully.
🔧 Temporary Workarounds
Disable telocom service if not needed
androidDisable the vulnerable telocom service to prevent exploitation
adb shell pm disable com.android.telocom
adb shell service call telocom 1 i32 0
Apply SELinux/AppArmor restrictions
linuxImplement strict SELinux or AppArmor policies to restrict telocom service permissions
setenforce 1
Check and modify SELinux policies for telocom domain
🧯 If You Can't Patch
- Implement strict network segmentation to limit lateral movement
- Deploy endpoint detection and response (EDR) solutions to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against vendor advisory. Examine telocom service permissions and SELinux contexts.Check Version:
adb shell getprop ro.build.version.security_patchVerify Fix Applied:
Verify firmware version is updated to patched version. Test privilege escalation attempts to confirm mitigation.📡 Detection & Monitoring
Log Indicators:
- Unusual telocom service activity
- Privilege escalation attempts in system logs
- Unexpected process execution with elevated privileges
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
source="android_system" AND (process="telocom" OR event="privilege_escalation")