CVE-2021-22333
📋 TL;DR
This CVE describes an Improper Validation of Array Index vulnerability in Huawei smartphones that allows attackers to execute arbitrary code with system privileges. The vulnerability affects Huawei smartphone users who haven't applied security patches. Successful exploitation could lead to complete device compromise.
💻 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
Magic Ui by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
Magic Ui by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains full system control, installs persistent malware, steals all data, and uses device as pivot point in network attacks.
Likely Case
Targeted attacks against specific users to install spyware or ransomware, potentially leading to data theft and device compromise.
If Mitigated
With proper patching and security controls, impact is limited to denial of service at most.
🎯 Exploit Status
CVSS 9.8 indicates critical severity with network attack vector and no authentication required. CWE-129 suggests array index validation issues that could lead to buffer overflows or memory corruption.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Huawei's April 2021 security update for specific patched versions
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2021/4/
Restart Required: Yes
Instructions:
1. Check for available system updates in Settings > System & updates > Software update. 2. Download and install the latest security patch. 3. Restart device after installation completes.
🔧 Temporary Workarounds
Disable unknown sources
allPrevent installation of apps from untrusted sources to reduce attack surface
Settings > Security > Install unknown apps > Disable for all apps
Enable Google Play Protect
allUse built-in malware scanning for apps from Google Play Store
Google Play Store > Menu > Play Protect > Scan device for security threats
🧯 If You Can't Patch
- Isolate affected devices from critical networks and sensitive data
- Implement mobile device management (MDM) with strict app whitelisting and network segmentation
🔍 How to Verify
Check if Vulnerable:
Check device model and software version against Huawei's April 2021 security bulletinCheck Version:
Settings > About phone > Software information > Build numberVerify Fix Applied:
Verify software version is updated to April 2021 security patch or later via Settings > About phone > Build number📡 Detection & Monitoring
Log Indicators:
- Unusual process creation with elevated privileges
- Suspicious memory access patterns
- Unexpected system service crashes
Network Indicators:
- Unexpected outbound connections from mobile devices
- Anomalous data exfiltration patterns
SIEM Query:
device_vendor:Huawei AND event_type:process_creation AND privilege_level:system