CVE-2021-36993
📋 TL;DR
This CVE describes a memory leak vulnerability in Huawei smartphones that could allow attackers to gradually consume system memory resources. Successful exploitation could lead to service degradation or denial of service conditions affecting device availability. The vulnerability affects Huawei smartphone users running vulnerable software versions.
💻 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 device unresponsiveness or crash requiring reboot, potentially disrupting critical phone functions including emergency calls.
Likely Case
Gradual performance degradation, app crashes, and reduced battery life due to memory exhaustion over time.
If Mitigated
Minor performance impact that may go unnoticed by users, with automatic memory management eventually recovering resources.
🎯 Exploit Status
Exploitation likely requires local access or malicious app installation; no public exploit details available
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: July 2021 security updates
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2021/7/
Restart Required: Yes
Instructions:
1. Check for system updates in Settings > System & updates > Software update. 2. Download and install July 2021 security update. 3. Restart device after installation completes.
🔧 Temporary Workarounds
Disable unnecessary apps and services
allReduce attack surface by disabling unused applications and background services
Regular device restarts
allPeriodic reboots can clear accumulated memory leaks before they cause significant impact
🧯 If You Can't Patch
- Implement strict app installation policies and only install from trusted sources
- Monitor device performance and restart when showing signs of memory exhaustion
🔍 How to Verify
Check if Vulnerable:
Check device security patch level in Settings > About phone > Build number; if before July 2021, likely vulnerableCheck Version:
No command line available; check via device Settings interfaceVerify Fix Applied:
Verify security patch level shows July 2021 or later in Settings > About phone📡 Detection & Monitoring
Log Indicators:
- Unusual memory consumption patterns in system logs
- Frequent OutOfMemory errors in application logs
Network Indicators:
- No network indicators for this local vulnerability
SIEM Query:
Not applicable for mobile device memory leak vulnerability