CVE-2020-27483
📋 TL;DR
This vulnerability in Garmin Forerunner 235 devices allows attackers to potentially execute arbitrary code by exploiting an array index error in the ConnectIQ TVM interpreter. Attackers could upload malicious ConnectIQ applications to the ConnectIQ store to trigger the vulnerability. Users of Garmin Forerunner 235 devices with firmware versions before 8.20 are affected.
💻 Affected Systems
- Garmin Forerunner 235
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution allowing complete device compromise, data theft, and potential lateral movement if device connects to other systems.
Likely Case
Information disclosure of runtime memory contents, potentially leading to further exploitation or device fingerprinting.
If Mitigated
Limited impact if devices are isolated from untrusted applications and network connections.
🎯 Exploit Status
Exploitation requires creating and uploading a malicious ConnectIQ application to the app store, which involves some technical skill but detailed advisory is available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 8.20 and later
Vendor Advisory: https://github.com/atredispartners/advisories/blob/master/ATREDIS-2020-0007.md
Restart Required: Yes
Instructions:
1. Connect Garmin Forerunner 235 to Garmin Express software on computer. 2. Check for firmware updates. 3. Install firmware version 8.20 or later. 4. Restart device after update completes.
🔧 Temporary Workarounds
Disable ConnectIQ app installation
allPrevent installation of third-party ConnectIQ applications that could be malicious.
Navigate to Settings > Apps > ConnectIQ Store > Disable
Restrict app sources
allOnly install ConnectIQ applications from trusted, verified sources.
🧯 If You Can't Patch
- Disconnect device from untrusted networks and Bluetooth connections
- Avoid installing new ConnectIQ applications until patched
🔍 How to Verify
Check if Vulnerable:
Check firmware version on device: Settings > System > About > Software VersionCheck Version:
Settings > System > About > Software VersionVerify Fix Applied:
Verify firmware version is 8.20 or higher after update📡 Detection & Monitoring
Log Indicators:
- Unusual application crashes
- Memory access violations in ConnectIQ logs
Network Indicators:
- Suspicious app downloads from ConnectIQ store
- Unusual device communication patterns
SIEM Query:
Not applicable for individual wearable devices