CVE-2011-10035
📋 TL;DR
This CVE describes a local privilege escalation vulnerability in Nagios XI where low-privileged users can exploit race conditions during crontab installation/update scripts. Attackers can manipulate filesystem state to execute arbitrary commands with elevated privileges. Only affects Nagios XI installations with local user access prior to version 2011R1.9.
💻 Affected Systems
- Nagios XI
📦 What is this software?
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
Nagios Xi by Nagios
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains root privileges, enabling complete system compromise, data theft, persistence mechanisms, and lateral movement.
Likely Case
Local user escalates to root or administrative privileges, allowing monitoring system manipulation, credential harvesting, and further privilege abuse.
If Mitigated
With proper access controls and patching, impact limited to denial of service or minimal privilege escalation if exploitation fails.
🎯 Exploit Status
Exploitation requires local access and understanding of race condition timing. Public exploit details exist in vulnerability reports.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2011R1.9 and later
Vendor Advisory: https://www.nagios.com/changelog/nagios-xi/
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Download Nagios XI 2011R1.9 or later from Nagios website. 3. Follow official upgrade instructions. 4. Restart Nagios services. 5. Verify version update.
🔧 Temporary Workarounds
Restrict local user access
linuxLimit local user accounts on Nagios XI servers to only necessary administrative users
# Review and remove unnecessary local users
sudo userdel <unnecessary_user>
# Restrict SSH access to admin users only
File permission hardening
linuxSet strict permissions on crontab installation scripts and directories
sudo chmod 750 /usr/local/nagiosxi/scripts/*
sudo chown root:root /usr/local/nagiosxi/scripts/*
sudo chmod 644 /etc/cron.d/nagiosxi
🧯 If You Can't Patch
- Implement strict access controls to prevent local user access to Nagios XI servers
- Monitor for suspicious privilege escalation attempts and file modifications in crontab directories
🔍 How to Verify
Check if Vulnerable:
Check Nagios XI version: grep 'nagios_version' /usr/local/nagiosxi/html/config.inc.php | grep -E '2011R1\.(0-8)'Check Version:
grep 'nagios_version' /usr/local/nagiosxi/html/config.inc.phpVerify Fix Applied:
Verify version is 2011R1.9 or later: grep 'nagios_version' /usr/local/nagiosxi/html/config.inc.php📡 Detection & Monitoring
Log Indicators:
- Unusual crontab modifications by non-root users
- Multiple rapid file operations in /etc/cron.d/ or Nagios script directories
- Failed privilege escalation attempts in system logs
Network Indicators:
- None - local exploitation only
SIEM Query:
source="syslog" AND ("crontab" OR "/etc/cron.d/") AND user!="root" AND (action="modify" OR action="create")