CVE-2025-5868
📋 TL;DR
This critical vulnerability in RT-Thread 5.1.0 allows improper array index validation in the sys_thread_sigprocmask function, potentially enabling memory corruption attacks. It affects systems running RT-Thread 5.1.0 with LWP (Lightweight Process) components enabled. Attackers could exploit this to execute arbitrary code or cause denial of service.
💻 Affected Systems
- RT-Thread
📦 What is this software?
Rt Thread by Rt Thread
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, privilege escalation, or persistent backdoor installation.
Likely Case
Denial of service through system crashes or memory corruption leading to unstable system behavior.
If Mitigated
Limited impact if systems are isolated, have memory protection mechanisms, or lack network exposure.
🎯 Exploit Status
Exploitation requires understanding of RT-Thread's LWP implementation and memory layout.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.1.1 or later
Vendor Advisory: https://github.com/RT-Thread/rt-thread/issues/10303
Restart Required: Yes
Instructions:
1. Update RT-Thread to version 5.1.1 or later. 2. Rebuild and redeploy the RT-Thread system. 3. Restart affected devices.
🔧 Temporary Workarounds
Disable LWP Component
allDisable the Lightweight Process component in RT-Thread configuration to remove vulnerable code path.
In RT-Thread configuration: Set RT_USING_LWP to 0
🧯 If You Can't Patch
- Implement strict network segmentation to isolate RT-Thread devices
- Deploy memory protection mechanisms like ASLR or stack canaries if supported
🔍 How to Verify
Check if Vulnerable:
Check RT-Thread version and configuration: if version is 5.1.0 and RT_USING_LWP is enabled, system is vulnerable.Check Version:
rt-thread --version or check RT_THREAD_VERSION in source codeVerify Fix Applied:
Verify RT-Thread version is 5.1.1 or later and check that sys_thread_sigprocmask function has proper array bounds validation.📡 Detection & Monitoring
Log Indicators:
- Unexpected system crashes
- Memory access violation logs
- Abnormal thread termination
Network Indicators:
- Unusual network traffic to RT-Thread devices
- Exploitation attempts targeting port 8080 (default RT-Thread console)
SIEM Query:
source="rt-thread" AND (event_type="crash" OR event_type="memory_violation")