CVE-2019-7713
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code or cause denial of service through a heap-based buffer overflow in the Green Hills INTEGRITY RTOS TELNET server. Attackers can exploit custom shell prompt modifiers to corrupt memory and potentially gain control of affected systems. Organizations using INTEGRITY RTOS with IPCOMShell TELNET server are affected.
💻 Affected Systems
- Green Hills INTEGRITY RTOS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or persistent backdoor installation on critical embedded systems.
Likely Case
System crash causing denial of service in industrial control, automotive, or aerospace systems where INTEGRITY RTOS is commonly deployed.
If Mitigated
Limited impact if TELNET access is restricted to trusted networks and systems have proper segmentation and monitoring.
🎯 Exploit Status
Public GitHub repository contains exploit details. Buffer overflow via crafted TELNET commands is straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Contact Green Hills Software for specific patched version
Vendor Advisory: https://www.ghs.com/products/rtos/integrity.html
Restart Required: Yes
Instructions:
1. Contact Green Hills Software support for patch
2. Apply provided patch to INTEGRITY RTOS installation
3. Restart affected systems
4. Verify TELNET service functionality
🔧 Temporary Workarounds
Disable TELNET Server
allDisable IPCOMShell TELNET server if not required for operations
# Configuration varies by system - consult INTEGRITY RTOS documentation
# Typically involves modifying system configuration files or build settings
Network Access Control
linuxRestrict TELNET access to trusted IP addresses only
# Configure firewall rules to block TELNET (port 23) from untrusted networks
# Example: iptables -A INPUT -p tcp --dport 23 -s trusted_network -j ACCEPT
# iptables -A INPUT -p tcp --dport 23 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected systems from untrusted networks
- Replace TELNET with SSH for secure remote access if supported
🔍 How to Verify
Check if Vulnerable:
Check if system runs INTEGRITY RTOS 5.0.4 with IPCOMShell TELNET enabled and custom prompt modifiers configuredCheck Version:
# System-specific - consult INTEGRITY RTOS documentation for version check commandsVerify Fix Applied:
Verify with Green Hills Software that patched version is installed and test TELNET service with crafted prompts📡 Detection & Monitoring
Log Indicators:
- Unusual TELNET connection attempts
- System crashes or restarts of TELNET service
- Memory corruption errors in system logs
Network Indicators:
- Unusual TELNET traffic patterns
- Crafted TELNET packets with shell prompt manipulation
SIEM Query:
source="telnet" AND (event="crash" OR event="buffer_overflow" OR bytes>threshold)