CVE-2021-40047
📋 TL;DR
CVE-2021-40047 is a memory leak vulnerability in Huawei's Bastet module where memory isn't properly released after its effective lifetime. This vulnerability could allow attackers to degrade system performance or cause denial-of-service conditions. It affects Huawei devices running HarmonyOS and certain Android-based EMUI systems.
💻 Affected Systems
- Huawei smartphones
- Huawei tablets
📦 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
System instability leading to device crashes, denial-of-service, or potential privilege escalation through memory exhaustion attacks.
Likely Case
Gradual performance degradation, increased memory consumption, and potential application crashes over time.
If Mitigated
Minimal impact with proper memory management controls and monitoring in place.
🎯 Exploit Status
Exploitation requires local access or malicious application installation. No public exploit code has been disclosed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: HarmonyOS 2.0.0.230 and later, EMUI security patches March 2022 and later
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2022/3/
Restart Required: Yes
Instructions:
1. Check for system updates in device Settings > System & updates > Software update. 2. Download and install available security updates. 3. Restart device after installation completes.
🔧 Temporary Workarounds
Disable unnecessary background services
allReduce memory pressure by limiting background processes
Regular device restarts
allClear accumulated memory leaks through periodic restarts
🧯 If You Can't Patch
- Monitor device memory usage and performance metrics
- Restrict installation of untrusted applications
🔍 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 versionVerify Fix Applied:
Verify OS version is HarmonyOS 2.0.0.230+ or check security patch date is March 2022 or later📡 Detection & Monitoring
Log Indicators:
- Abnormal memory consumption patterns
- Bastet module crashes
- Out of memory errors
Network Indicators:
- Unusual network connection failures
SIEM Query:
Process memory usage > threshold AND process_name contains 'bastet'🔗 References
- https://consumer.huawei.com/en/support/bulletin/2022/3/
- https://device.harmonyos.com/cn/docs/security/update/security-bulletins-phones-202203-0000001257385193
- https://consumer.huawei.com/en/support/bulletin/2022/3/
- https://device.harmonyos.com/cn/docs/security/update/security-bulletins-phones-202203-0000001257385193
