CVE-2021-37079
📋 TL;DR
This vulnerability in Huawei smartphones allows attackers with system_app permission to delete arbitrary files due to improper input validation. It affects Huawei devices running HarmonyOS, potentially enabling malicious apps to delete critical system files. The high CVSS score reflects the significant impact on device integrity.
💻 Affected Systems
- Huawei smartphones running HarmonyOS
📦 What is this software?
Harmonyos by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise through deletion of critical system files, potentially rendering the device unusable or enabling persistent malware installation.
Likely Case
Malicious apps abusing system_app permissions to delete user data or system configuration files, causing data loss or device instability.
If Mitigated
Limited impact if proper app sandboxing and permission controls prevent unauthorized access to system_app privileges.
🎯 Exploit Status
Requires developing or modifying an app with system_app permissions, which adds complexity but is feasible for determined attackers.
🛠️ 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-202109-0000001196270727
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
Restrict app installations
allOnly install apps from trusted sources like Huawei AppGallery and avoid sideloading unknown apps.
Review app permissions
allRegularly audit installed apps and remove any with unnecessary system-level permissions.
🧯 If You Can't Patch
- Isolate affected devices from critical networks and data
- Implement mobile device management (MDM) to control app installations and permissions
🔍 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 navigation only - no command line available on consumer devicesVerify Fix Applied:
Confirm HarmonyOS version is 2.0.0.230 or later in Settings > About phone > HarmonyOS version.📡 Detection & Monitoring
Log Indicators:
- Unexpected file deletion events in system logs
- Apps requesting or using system_app permissions abnormally
Network Indicators:
- Unusual app update or installation patterns from untrusted sources
SIEM Query:
Not applicable for consumer mobile devices without enterprise logging integration