CVE-2018-17174
📋 TL;DR
A stack-based buffer overflow in the xtimor NMEA library (nmealib) version 0.5.3 allows attackers to cause denial of service or potentially execute arbitrary code by sending malformed data to the nmea_parse() function. This affects any product or application that uses this vulnerable library version to parse NMEA data from GPS devices or other sources.
💻 Affected Systems
- Any product using nmealib (xtimor NMEA library) version 0.5.3
📦 What is this software?
Nmealib by Nmealib Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or persistent backdoor installation.
Likely Case
Denial of service causing application crashes or system instability in affected products.
If Mitigated
Limited impact with proper input validation and memory protection mechanisms in place.
🎯 Exploit Status
Buffer overflow vulnerabilities in parsing libraries are commonly exploited, and the public references demonstrate the issue.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: nmealib 0.5.4 or later
Vendor Advisory: https://github.com/jacketizer/libnmea/issues/1
Restart Required: Yes
Instructions:
1. Identify applications using nmealib 0.5.3. 2. Update to nmealib 0.5.4 or later. 3. Recompile applications with the updated library. 4. Restart affected services or applications.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation for NMEA data before passing to nmea_parse() function
# Custom validation logic required - no standard command
Memory Protection
linuxEnable ASLR and stack protection mechanisms at OS level
# Linux: sysctl -w kernel.randomize_va_space=2
# Compile with: -fstack-protector-all
🧯 If You Can't Patch
- Network segmentation to isolate systems processing NMEA data
- Implement strict firewall rules to limit NMEA data sources to trusted devices only
🔍 How to Verify
Check if Vulnerable:
Check linked libraries of applications: ldd <application> | grep nmea, or check package manager for nmealib versionCheck Version:
pkg-config --modversion nmea || strings /usr/lib/libnmea.so | grep 'nmealib'Verify Fix Applied:
Verify nmealib version is 0.5.4 or later: dpkg -l | grep nmea (Debian/Ubuntu) or rpm -qa | grep nmea (RHEL/CentOS)📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Abnormal termination of GPS/NMEA processing services
Network Indicators:
- Unusual NMEA data patterns or malformed packets to GPS/NMEA ports
SIEM Query:
source="application.log" ("segmentation fault" OR "SIGSEGV") AND process="*nmea*"