CVE-2024-6443
📋 TL;DR
This vulnerability in Zephyr RTOS's UTF-8 string truncation function allows reading memory outside the intended buffer when processing empty strings. It affects systems running Zephyr RTOS with UTF-8 string handling enabled.
💻 Affected Systems
- Zephyr RTOS
📦 What is this software?
Zephyr by Zephyrproject
⚠️ Risk & Real-World Impact
Worst Case
Information disclosure of adjacent memory contents, potentially exposing sensitive data or system information.
Likely Case
Application crash or instability due to invalid memory access, leading to denial of service.
If Mitigated
No impact if UTF-8 string handling is disabled or empty strings are filtered before processing.
🎯 Exploit Status
Requires specific conditions: UTF-8 handling enabled and empty string processing. Not trivial to exploit remotely.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Latest Zephyr RTOS version with commit addressing GHSA-gg46-3rh2-v765
Vendor Advisory: https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-gg46-3rh2-v765
Restart Required: Yes
Instructions:
1. Update Zephyr RTOS to latest version. 2. Rebuild and redeploy affected firmware. 3. Restart devices.
🔧 Temporary Workarounds
Disable UTF-8 string handling
allRemove or disable UTF-8 string processing functionality if not required
Modify build configuration to exclude UTF-8 support
Validate string inputs
allAdd input validation to ensure empty strings are not passed to utf8_trunc
Add NULL/empty checks before calling utf8_trunc
🧯 If You Can't Patch
- Implement input validation to prevent empty strings from reaching vulnerable function
- Monitor system logs for crashes or abnormal behavior related to string processing
🔍 How to Verify
Check if Vulnerable:
Check if Zephyr RTOS version includes the vulnerable utf8.c code and UTF-8 handling is enabledCheck Version:
Check Zephyr RTOS version in build configuration or device firmwareVerify Fix Applied:
Verify Zephyr RTOS version includes the security fix commit for GHSA-gg46-3rh2-v765📡 Detection & Monitoring
Log Indicators:
- System crashes
- Memory access violation errors
- UTF-8 processing failures
Network Indicators:
- None - local vulnerability
SIEM Query:
Search for system crashes or memory errors in device logs