CVE-2024-8798
📋 TL;DR
This vulnerability allows attackers to cause a heap-based buffer overflow in Zephyr RTOS Bluetooth Object Transfer Service (OTS) client by sending malformed data. It affects devices running vulnerable Zephyr versions with Bluetooth OTS client enabled. Successful exploitation could lead to denial of service or arbitrary code execution.
💻 Affected Systems
- Zephyr RTOS
📦 What is this software?
Zephyr by Zephyrproject
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, data exfiltration, or persistent backdoor installation.
Likely Case
Denial of service causing Bluetooth service crashes or device instability.
If Mitigated
No impact if input validation is properly implemented or vulnerable component is disabled.
🎯 Exploit Status
Exploitation requires Bluetooth access and knowledge of OTS protocol. No public exploits known as of advisory date.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v3.7.0 and later
Vendor Advisory: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r7pm-f93f-f7fp
Restart Required: Yes
Instructions:
1. Update Zephyr RTOS to v3.7.0 or later. 2. Rebuild firmware with updated Zephyr source. 3. Flash updated firmware to affected devices. 4. Verify Bluetooth OTS client functionality.
🔧 Temporary Workarounds
Disable OTS Client
allDisable the vulnerable Bluetooth Object Transfer Service client component.
Set CONFIG_BT_OTS_CLIENT=n in project configuration
🧯 If You Can't Patch
- Implement network segmentation to isolate Bluetooth-enabled devices from critical networks.
- Deploy Bluetooth intrusion detection systems to monitor for anomalous OTS protocol traffic.
🔍 How to Verify
Check if Vulnerable:
Check if CONFIG_BT_OTS_CLIENT=y and Zephyr version < 3.7.0 in build configuration.Check Version:
grep -r "ZEPHYR_VERSION" build/zephyr/include/generated/version.hVerify Fix Applied:
Verify Zephyr version >= 3.7.0 and check that olcp_ind_handler includes proper length validation in ots_client.c.📡 Detection & Monitoring
Log Indicators:
- Bluetooth stack crashes
- OTS client error messages
- Memory corruption warnings in system logs
Network Indicators:
- Abnormal Bluetooth OTS packet sizes
- Repeated OTS connection attempts with malformed data
SIEM Query:
source="bluetooth_logs" AND (event="stack_crash" OR message="*ots*" OR message="*buffer*overflow*")