CVE-2021-22488
📋 TL;DR
This vulnerability in Huawei smartphones allows attackers to access and modify files through improper symlink handling during backup restoration. Attackers could tamper with restored files by manipulating symbolic links. This affects Huawei smartphone users who restore backups from untrusted sources.
💻 Affected Systems
- Huawei smartphones
📦 What is this software?
Emui by Huawei
Emui by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of user data integrity, allowing attackers to modify critical system files, install malware, or steal sensitive information through manipulated backups.
Likely Case
Data corruption or unauthorized access to user files, potentially leading to privacy violations or device instability.
If Mitigated
Limited impact with proper backup source validation and file integrity checks in place.
🎯 Exploit Status
Exploitation requires creating malicious symlinks and convincing user to restore from compromised backup, or having local device access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions patched in July 2021 security updates
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2021/7/
Restart Required: Yes
Instructions:
1. Check for available system updates in Settings > System & updates > Software update. 2. Install the latest security update from July 2021 or later. 3. Restart device after installation.
🔧 Temporary Workarounds
Avoid untrusted backups
allOnly restore backups from trusted, verified sources to prevent symlink manipulation attacks.
Disable automatic backup restoration
allManually verify backup contents before restoration when possible.
🧯 If You Can't Patch
- Only restore backups from trusted, verified sources you created yourself
- Use alternative backup solutions with proper symlink validation and integrity checking
🔍 How to Verify
Check if Vulnerable:
Check if device has received July 2021 or later security updates via Settings > System & updates > Software update > Latest update info.Check Version:
Not applicable via command line on consumer smartphones; use Settings > About phone > Build numberVerify Fix Applied:
Confirm installation of July 2021 security patch by checking build number in Settings > About phone.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns during backup restoration
- Symlink creation in backup directories
Network Indicators:
- Unexpected backup file transfers from untrusted sources
SIEM Query:
Not typically applicable for consumer smartphone environments