CVE-2021-22401
📋 TL;DR
CVE-2021-22401 is a remote denial-of-service vulnerability affecting certain Huawei smartphones. Successful exploitation could allow an attacker to disrupt services on affected devices, potentially rendering them unresponsive or unstable. This vulnerability affects Huawei smartphone users with specific software versions.
💻 Affected Systems
- Huawei smartphones
📦 What is this software?
Emui by Huawei
Magic Ui by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption on affected smartphones, potentially requiring device restart or factory reset to restore functionality.
Likely Case
Temporary service degradation or application crashes on affected devices.
If Mitigated
Minimal impact with proper network segmentation and updated devices.
🎯 Exploit Status
Remote exploitation possible; specific technical details not publicly disclosed in provided references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Huawei security bulletins for specific patched versions
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2021/7/
Restart Required: Yes
Instructions:
1. Check for security updates in device Settings > System & updates > Software update. 2. Install any available security patches. 3. Restart device after update completion.
🔧 Temporary Workarounds
Network segmentation
allLimit network exposure of affected devices to untrusted networks
Disable unnecessary services
allTurn off Bluetooth, Wi-Fi, and other network services when not in use
🧯 If You Can't Patch
- Isolate affected devices from untrusted networks
- Monitor device behavior for unusual crashes or performance issues
🔍 How to Verify
Check if Vulnerable:
Check device software version in Settings > About phone > Build number and compare with Huawei security bulletinsCheck Version:
Settings > About phone > Build numberVerify Fix Applied:
Verify security patch level in Settings > About phone > Build number shows July 2021 or later security patch📡 Detection & Monitoring
Log Indicators:
- Unexpected service crashes
- System stability issues
- Network connection anomalies
Network Indicators:
- Unusual network traffic patterns to/from Huawei devices
- Connection attempts to unexpected ports
SIEM Query:
device_vendor:Huawei AND (event_type:crash OR event_type:service_stop)