CVE-2024-48981
📋 TL;DR
This vulnerability in MBed OS 6.16.0 allows attackers to execute arbitrary write operations via specially crafted HCI packets, leading to potential remote code execution. It affects systems using MBed OS with BLE connectivity enabled. The buffer overflow occurs during HCI packet header parsing when invalid identifiers are processed.
💻 Affected Systems
- MBed OS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or device takeover
Likely Case
Denial of service, memory corruption, or limited code execution depending on exploit constraints
If Mitigated
No impact if patched or if BLE functionality is disabled
🎯 Exploit Status
Exploitation requires sending malicious HCI packets to the BLE interface. No public exploit code found in references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in PR #374, should be included in versions after 6.16.0
Vendor Advisory: https://github.com/mbed-ce/mbed-os/pull/374
Restart Required: Yes
Instructions:
1. Update MBed OS to version containing PR #374 fix
2. Rebuild and redeploy firmware
3. Restart affected devices
🔧 Temporary Workarounds
Disable BLE connectivity
allDisable Bluetooth Low Energy feature if not required
Modify MBed OS configuration to disable FEATURE_BLE
Implement packet filtering
allFilter invalid HCI packet identifiers before processing
Implement pre-processing filter for HCI packets with invalid first byte identifiers
🧯 If You Can't Patch
- Segment network to isolate BLE-enabled devices from untrusted networks
- Implement strict access controls for BLE interfaces and monitor for anomalous HCI traffic
🔍 How to Verify
Check if Vulnerable:
Check if using MBed OS 6.16.0 with BLE enabled and examine hci_tr.c for vulnerable code patternCheck Version:
Check MBed OS version in mbed-os.lib or via build configurationVerify Fix Applied:
Verify PR #374 changes are present in hci_tr.c and test with invalid HCI packet identifiers📡 Detection & Monitoring
Log Indicators:
- Unusual HCI packet processing errors
- Memory corruption logs
- BLE stack crashes
Network Indicators:
- Malformed HCI packets with invalid first byte identifiers
- Unusual BLE traffic patterns
SIEM Query:
Search for: 'hciTrSerialRxIncoming' errors OR 'buffer overflow' in BLE stack logs