CVE-2023-4264
📋 TL;DR
CVE-2023-4264 is a buffer overflow vulnerability in the Zephyr RTOS Bluetooth subsystem that could allow attackers to execute arbitrary code or cause denial of service. This affects devices running Zephyr RTOS with Bluetooth functionality enabled, particularly IoT and embedded systems.
💻 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 device bricking
Likely Case
Denial of service through device crashes or instability in Bluetooth functionality
If Mitigated
Limited impact with proper network segmentation and Bluetooth security controls
🎯 Exploit Status
Exploitation requires Bluetooth access to target device; proof-of-concept details available in public disclosures
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Zephyr RTOS versions after the security advisory
Vendor Advisory: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rgx6-3w4j-gf5j
Restart Required: Yes
Instructions:
1. Update Zephyr RTOS to patched version 2. Rebuild firmware with updated Zephyr source 3. Flash updated firmware to affected devices 4. Verify Bluetooth functionality post-update
🔧 Temporary Workarounds
Disable Bluetooth
allTemporarily disable Bluetooth functionality if not required
CONFIG_BT=n in prj.conf or overlay files
Network Segmentation
allIsolate Bluetooth-enabled devices from critical networks
🧯 If You Can't Patch
- Implement strict Bluetooth access controls and pairing requirements
- Monitor for abnormal Bluetooth traffic and device behavior
🔍 How to Verify
Check if Vulnerable:
Check Zephyr version and Bluetooth configuration: grep -r 'CONFIG_BT' build/zephyr/.config && cat VERSIONCheck Version:
cat VERSION or check Zephyr git commit hashVerify Fix Applied:
Verify Zephyr version is updated and rebuild firmware with latest security patches📡 Detection & Monitoring
Log Indicators:
- Bluetooth stack crashes
- Memory corruption errors
- Unexpected device reboots
Network Indicators:
- Abnormal Bluetooth packet patterns
- Unexpected Bluetooth connections
SIEM Query:
Device logs containing 'panic', 'assert', or Bluetooth subsystem errors🔗 References
- http://packetstormsecurity.com/files/175657/Zephyr-RTOS-3.x.0-Buffer-Overflows.html
- http://seclists.org/fulldisclosure/2023/Nov/1
- http://www.openwall.com/lists/oss-security/2023/11/07/1
- https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rgx6-3w4j-gf5j
- http://packetstormsecurity.com/files/175657/Zephyr-RTOS-3.x.0-Buffer-Overflows.html
- http://seclists.org/fulldisclosure/2023/Nov/1
- http://www.openwall.com/lists/oss-security/2023/11/07/1
- https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-rgx6-3w4j-gf5j
