CVE-2023-51391
📋 TL;DR
A vulnerability in Micrium OS Network HTTP Server allows invalid pointer dereference during HTTP header processing, potentially causing device crashes and denial of service. This affects devices running vulnerable versions of Micrium OS with the HTTP server enabled. The bug could be triggered by sending specially crafted HTTP requests to the server.
💻 Affected Systems
- Micrium OS Network HTTP Server
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical reset or reboot, leading to sustained denial of service for all services on the affected device.
Likely Case
Temporary service disruption with automatic or manual restart required to restore functionality.
If Mitigated
Minimal impact with proper network segmentation and request filtering preventing exploitation attempts.
🎯 Exploit Status
Exploitation requires sending malformed HTTP requests to the vulnerable server, which is straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not explicitly stated in references, but vendor advisories indicate patches are available.
Vendor Advisory: https://community.silabs.com/068Vm000004688g
Restart Required: Yes
Instructions:
1. Check current Micrium OS version
2. Review vendor advisory for patched versions
3. Apply vendor-provided patch or update to fixed version
4. Restart affected services or devices
🔧 Temporary Workarounds
Disable HTTP Server
allIf HTTP server functionality is not required, disable it completely to eliminate the attack surface.
Configuration dependent - consult Micrium OS documentation for disabling HTTP server
Network Segmentation
linuxRestrict network access to HTTP server to only trusted sources using firewall rules.
iptables -A INPUT -p tcp --dport 80 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to limit HTTP server exposure
- Deploy web application firewall or reverse proxy to filter malicious HTTP requests
🔍 How to Verify
Check if Vulnerable:
Check if Micrium OS HTTP server is running and compare version against vendor advisory for vulnerable versions.Check Version:
System-specific - consult Micrium OS documentation for version checking commandsVerify Fix Applied:
Verify patch application by checking version numbers and testing with controlled HTTP requests that previously triggered the issue.📡 Detection & Monitoring
Log Indicators:
- Unexpected HTTP server crashes or restarts
- Malformed HTTP request patterns in server logs
- Increased error rates in HTTP response codes
Network Indicators:
- Unusual HTTP traffic patterns to device ports
- Requests with malformed headers or unusual payloads
SIEM Query:
source="http_server" AND (event="crash" OR event="restart" OR status=500)