CVE-2019-15949 : Exploit Details and Defense Strategies

Nagios XI before version 5.6.6 is vulnerable to remote command execution as root, allowing attackers to execute malicious commands with elevated privileges.

Understanding CVE-2019-15949

This CVE describes a critical vulnerability in Nagios XI that enables unauthorized users to execute commands as root.

What is CVE-2019-15949?

Remote command execution as root is possible in Nagios XI versions earlier than 5.6.6.
Attackers can exploit this vulnerability by accessing the server as the 'nagios' or 'admin' user through the web interface.
The attack involves triggering the 'getprofile.sh' script by downloading a system profile using the 'profile.php?cmd=download' endpoint.

The Impact of CVE-2019-15949

Allows attackers to run commands with root privileges on the target system.
Attackers can modify the 'check_plugin' executable to inject and execute malicious commands.

Technical Details of CVE-2019-15949

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The 'getprofile.sh' script runs with root privileges through a sudo entry that does not require a password.
The script executes the 'check_plugin' command, which is owned by the 'nagios' user.

Affected Systems and Versions

Nagios XI versions earlier than 5.6.6 are affected by this vulnerability.

Exploitation Mechanism

Attackers with access to the 'nagios' user or admin user on the server can exploit this vulnerability.
By modifying the 'check_plugin' executable, attackers can insert and execute malicious commands.

Mitigation and Prevention

Protecting systems from CVE-2019-15949 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Nagios XI to version 5.6.6 or later to mitigate the vulnerability.
Monitor system logs for any suspicious activities.

Long-Term Security Practices

Implement the principle of least privilege to restrict user permissions.
Regularly audit and review system configurations and access controls.

Patching and Updates

Apply security patches and updates provided by Nagios to address known vulnerabilities.