CVE-2021-39982
📋 TL;DR
CVE-2021-39982 is an improper privilege management vulnerability in Huawei's Phone Manager application that allows attackers to read and write arbitrary files by tampering with notifications. This affects Huawei devices running HarmonyOS with the Phone Manager app installed. Successful exploitation could lead to data theft, system compromise, or privilege escalation.
💻 Affected Systems
- Huawei Phone Manager
📦 What is this software?
Harmonyos by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise allowing attackers to steal sensitive data, install malware, or gain persistent access to the device.
Likely Case
Local privilege escalation allowing attackers to access protected files or modify system settings.
If Mitigated
Limited impact with proper app sandboxing and notification permission controls in place.
🎯 Exploit Status
Requires local access or malicious app installation to exploit. Exploitation involves manipulating Phone Manager notifications to bypass file access restrictions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: HarmonyOS 2.0.0.230 and later
Vendor Advisory: https://device.harmonyos.com/en/docs/security/update/security-bulletins-202110-0000001162998526
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System & updates > Software update. 2. Download and install HarmonyOS 2.0.0.230 or later. 3. Restart device after installation completes.
🔧 Temporary Workarounds
Disable Phone Manager Notifications
allTemporarily disable Phone Manager notification permissions to prevent exploitation via notification tampering.
Settings > Apps > Phone Manager > Notifications > Turn off all notification permissions
Disable Phone Manager App
allDisable the Phone Manager application if not required for device functionality.
Settings > Apps > Phone Manager > Disable
🧯 If You Can't Patch
- Implement strict app installation policies to prevent malicious apps from being installed
- Enable device encryption and strong authentication to limit impact of local attacks
🔍 How to Verify
Check if Vulnerable:
Check HarmonyOS version in Settings > About phone > HarmonyOS version. If version is earlier than 2.0.0.230, device is vulnerable.Check Version:
Settings > About phone > HarmonyOS versionVerify Fix Applied:
Verify HarmonyOS version is 2.0.0.230 or later in Settings > About phone > HarmonyOS version.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns by Phone Manager process
- Multiple failed notification permission requests
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
Not applicable for typical mobile device management scenarios