CVE-2021-39989
📋 TL;DR
This vulnerability in the HwNearbyMain module of HarmonyOS allows unauthorized actors to access sensitive information, potentially leading to process restarts. It affects devices running vulnerable versions of HarmonyOS, particularly those with the HwNearbyMain module enabled.
💻 Affected Systems
- HarmonyOS devices with HwNearbyMain module
📦 What is this software?
Harmonyos by Huawei
⚠️ Risk & Real-World Impact
Worst Case
Exploitation could result in unauthorized access to sensitive system or user data, causing process disruptions or system instability.
Likely Case
Most probable impact is information leakage, such as exposure of device or user details, with potential for minor service interruptions.
If Mitigated
With proper controls like patching or network segmentation, impact is limited to low-risk information exposure or no exploitation.
🎯 Exploit Status
Exploitation likely requires some level of access or interaction with the vulnerable module; no public proof-of-concept is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to the vendor advisory for specific patched versions.
Vendor Advisory: https://device.harmonyos.com/en/docs/security/update/security-bulletins-202111-0000001217889667
Restart Required: Yes
Instructions:
1. Check the vendor advisory for affected versions and patches. 2. Apply the official security update via the device's update mechanism. 3. Restart the device as required to complete the patch installation.
🔧 Temporary Workarounds
Disable HwNearbyMain Module
allTemporarily disable the vulnerable module to reduce exposure until patching is possible.
Specific commands not provided; use device settings or administrative tools to disable the module if available.
🧯 If You Can't Patch
- Implement network segmentation to isolate affected devices from untrusted networks.
- Monitor logs for unusual activity related to the HwNearbyMain module and restrict user permissions where possible.
🔍 How to Verify
Check if Vulnerable:
Check the device's HarmonyOS version against the vendor advisory; if it matches affected versions and the HwNearbyMain module is enabled, it is vulnerable.Check Version:
Use the device's system settings or command 'getprop ro.build.version.harmony' (if available) to check the HarmonyOS version.Verify Fix Applied:
After applying the patch, verify the device is running a patched version as listed in the vendor advisory and confirm the HwNearbyMain module is updated.📡 Detection & Monitoring
Log Indicators:
- Log entries indicating unauthorized access attempts or errors in the HwNearbyMain module, such as process restarts or permission denials.
Network Indicators:
- Unusual network traffic to or from the device related to the HwNearbyMain service, especially from unauthorized sources.
SIEM Query:
Example: 'source="device_logs" AND (module="HwNearbyMain" AND (event="access_denied" OR event="process_restart"))'