CVE-2023-37239
📋 TL;DR
A format string vulnerability exists in Huawei's distributed file system that could allow attackers to crash the program. This affects Huawei devices running HarmonyOS where SELinux permissions can be bypassed. The vulnerability requires local access and SELinux bypass to exploit.
💻 Affected Systems
- Huawei HarmonyOS devices with distributed file system
📦 What is this software?
Emui by Huawei
Emui by Huawei
Harmonyos by Huawei
Harmonyos by Huawei
Harmonyos by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service through program crash, potentially disrupting distributed file system operations across affected devices.
Likely Case
Local denial of service affecting the specific vulnerable component, requiring SELinux bypass to trigger.
If Mitigated
Minimal impact if SELinux is properly configured and enforced, as the vulnerability requires bypassing SELinux protections.
🎯 Exploit Status
Requires local access and SELinux bypass capability. Format string vulnerabilities typically require specific input crafting.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: July 2023 security updates for HarmonyOS
Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2023/7/
Restart Required: Yes
Instructions:
1. Check for available updates in device settings. 2. Apply July 2023 security updates for HarmonyOS. 3. Restart device after update installation.
🔧 Temporary Workarounds
Strengthen SELinux policies
linuxEnhance SELinux configuration to prevent bypass attempts
Review and harden SELinux policies specific to distributed file system components
🧯 If You Can't Patch
- Implement strict access controls to limit local access to vulnerable systems
- Monitor for SELinux policy violation attempts and investigate any bypass attempts
🔍 How to Verify
Check if Vulnerable:
Check HarmonyOS version and verify if July 2023 security updates are installedCheck Version:
Check device settings > About phone > HarmonyOS versionVerify Fix Applied:
Confirm installation of July 2023 security updates and check version is updated📡 Detection & Monitoring
Log Indicators:
- SELinux denial logs for distributed file system processes
- Process crashes related to distributed file system components
Network Indicators:
- No direct network indicators - local exploitation only
SIEM Query:
Process:name="distributed_file_system" AND (EventID:1000 OR SELinux:denied)🔗 References
- https://consumer.huawei.com/en/support/bulletin/2023/7/
- https://device.harmonyos.com/en/docs/security/update/security-bulletins-202307-0000001587168858
- https://consumer.huawei.com/en/support/bulletin/2023/7/
- https://device.harmonyos.com/en/docs/security/update/security-bulletins-202307-0000001587168858
