CVE-2021-46887
📋 TL;DR
This vulnerability in Huawei's HW_KEYMASTER module allows attackers to read memory beyond allocated boundaries due to insufficient input validation. It affects Huawei devices using vulnerable firmware versions. Successful exploitation could lead to information disclosure or system compromise.
💻 Affected Systems
- Huawei smartphones and tablets with affected firmware
📦 What is this software?
Emui by Huawei
Emui by Huawei
Emui by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to data theft, privilege escalation, or persistent backdoor installation
Likely Case
Information disclosure of sensitive cryptographic keys or memory contents
If Mitigated
Limited impact with proper network segmentation and access controls
🎯 Exploit Status
Exploitation requires local access or ability to execute code on device
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Huawei security bulletins for specific patched versions
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2023/5/
Restart Required: Yes
Instructions:
1. Check Huawei security bulletin for affected devices. 2. Apply latest firmware updates via Settings > System & updates > Software update. 3. Reboot device after update completes.
🔧 Temporary Workarounds
Restrict device access
allLimit physical and network access to vulnerable devices
Disable unnecessary services
allReduce attack surface by disabling unused device features
🧯 If You Can't Patch
- Isolate affected devices on separate network segments
- Implement strict access controls and monitoring for device usage
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against Huawei's security bulletin listCheck Version:
Settings > About phone > Build numberVerify Fix Applied:
Verify firmware version is updated beyond vulnerable versions listed in advisory📡 Detection & Monitoring
Log Indicators:
- Unusual system crashes
- Abnormal memory access patterns in system logs
Network Indicators:
- Suspicious device communication patterns
SIEM Query:
Device logs showing memory access violations or keymaster module errors