CVE-2021-37119
📋 TL;DR
This vulnerability is a service logic flaw in Huawei smartphones that allows attackers to cause a denial-of-service (DoS) condition on the WLAN interface. Successful exploitation disrupts wireless connectivity on affected devices. The vulnerability affects Huawei smartphones running HarmonyOS or EMUI.
💻 Affected Systems
- Huawei smartphones
📦 What is this software?
Emui by Huawei
Emui by Huawei
Emui by Huawei
Emui by Huawei
Emui by Huawei
Emui by Huawei
Harmonyos by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Complete loss of WLAN connectivity on the device, requiring a reboot to restore functionality, potentially disrupting critical communications or services.
Likely Case
Temporary disruption of Wi-Fi connectivity, causing inconvenience but not permanent damage to the device.
If Mitigated
Minimal impact with proper network segmentation and updated devices; isolated to individual devices rather than network-wide.
🎯 Exploit Status
Exploitation requires sending specially crafted packets to the device's WLAN interface; no public exploit code has been released.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: HarmonyOS 2.0.0.230 and later, EMUI with October 2021 security patches
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2021/10/
Restart Required: Yes
Instructions:
1. Check for system updates in device Settings > System & updates > Software update. 2. Download and install available updates. 3. Reboot device after installation completes.
🔧 Temporary Workarounds
Disable WLAN when not in use
allTurn off Wi-Fi connectivity to prevent exploitation attempts
Settings > WLAN > Toggle off
Use cellular data instead of Wi-Fi
allSwitch to mobile data to maintain connectivity while avoiding the vulnerable WLAN interface
Settings > Mobile network > Enable mobile data
🧯 If You Can't Patch
- Segment network to isolate vulnerable devices from untrusted networks
- Implement network monitoring for unusual WLAN traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check device OS version in Settings > About phone > HarmonyOS version or EMUI versionCheck Version:
Settings > About phone > HarmonyOS version (or EMUI version)Verify Fix Applied:
Verify OS version is HarmonyOS 2.0.0.230 or later, or EMUI with October 2021 security patches📡 Detection & Monitoring
Log Indicators:
- Unusual WLAN disconnection events
- WLAN service crashes in system logs
Network Indicators:
- Abnormal WLAN packet patterns targeting Huawei devices
- Sudden Wi-Fi disconnections across multiple devices
SIEM Query:
source="device_logs" AND (event="wlan_disconnect" OR event="wlan_service_error") AND device_vendor="Huawei"🔗 References
- https://consumer.huawei.com/en/support/bulletin/2021/10/
- https://device.harmonyos.com/en/docs/security/update/security-bulletins-202110-0000001162998526
- https://consumer.huawei.com/en/support/bulletin/2021/10/
- https://device.harmonyos.com/en/docs/security/update/security-bulletins-202110-0000001162998526
